diff --git a/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/BaselineMetrics.cs b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/BaselineMetrics.cs
new file mode 100644
index 000000000..5937eebf1
--- /dev/null
+++ b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/BaselineMetrics.cs
@@ -0,0 +1,145 @@
+using System.Globalization;
+using System.Collections;
+using System.Diagnostics;
+using System.Reflection;
+using Opc.Ua;
+using Opc.Ua.Server;
+using Shouldly;
+internal static class BaselineMetrics
+{
+    private static FieldInfo Field(object owner, string name)
+    {
+        for (var type = owner.GetType(); type is not null; type = type.BaseType)
+            if (type.GetField(name, BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.DeclaredOnly) is { } member) return member;
+        throw new InvalidOperationException("Missing exact-.182 diagnostic field: " + name);
+    }
+    private static T Required<T>(object owner, string name) => Field(owner, name).GetValue(owner) is T value ? value
+        : throw new InvalidOperationException("Unexpected exact-.182 diagnostic field type: " + name);
+    internal static (int Browse, int History) Points(ISession session)
+    {
+        using (Required<System.Threading.Lock>(session, "m_lock").EnterScope())
+            return (Count(session, "m_browseContinuationPoints"), Count(session, "m_historyContinuationPoints"));
+    }
+    private static int Count(object owner, string name) => Field(owner, name).GetValue(owner) switch
+    { null => 0, ICollection values => values.Count, _ => throw new InvalidOperationException("Unexpected continuation collection type") };
+    internal static int CachedStoreReferences(CertificateValidator validator)
+    {
+        var gate = Required<SemaphoreSlim>(validator, "m_semaphore");
+        if (!gate.Wait(TimeSpan.FromSeconds(5))) throw new TimeoutException("Original validator diagnostic lock did not settle");
+        try
+        {
+            return new[] { "m_trustedCertificateStore", "m_issuerCertificateStore", "m_rejectedCertificateStore" }
+                .Select(name => Field(validator, name).GetValue(validator))
+                .Count(value => value switch
+                {
+                    null => false,
+                    CertificateStoreIdentifier store => Field(store, "m_store").GetValue(store) switch
+                    { null => false, ICertificateStore => true, _ => throw new InvalidOperationException("Original cached store type changed") },
+                    _ => throw new InvalidOperationException("Original validator store identifier type changed")
+                });
+        }
+        finally { gate.Release(); }
+    }
+    internal static int Counter(object manager, string name)
+    {
+        var property = manager.GetType().GetProperty(name, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)
+            ?? throw new InvalidOperationException("Missing original node-manager diagnostic property: " + name);
+        return property.PropertyType == typeof(int) && property.GetValue(manager) is int value ? value
+            : throw new InvalidOperationException("Unexpected original node-manager diagnostic property type: " + name);
+    }
+    internal static async Task<(int Total, int Pki)> DescriptorsAsync(CancellationToken ct, params string[] roots)
+    {
+        ct.ThrowIfCancellationRequested();
+        if (OperatingSystem.IsWindows()) return await WindowsDescriptors.CountAsync(ct, roots);
+        var canonicalRoots = roots.Select(root => CanonicalPath(root)).Distinct(StringComparer.Ordinal).ToArray();
+        if (OperatingSystem.IsLinux())
+        {
+            var targets = Directory.EnumerateFileSystemEntries("/proc/self/fd")
+                .Select(path => new FileInfo(path).LinkTarget).ToArray();
+            return (targets.Length, targets.Count(path => IsWithinRoots(path, canonicalRoots)));
+        }
+        if (OperatingSystem.IsMacOS())
+        {
+            using var process = new Process { StartInfo = new ProcessStartInfo("/usr/sbin/lsof")
+                { RedirectStandardOutput = true, RedirectStandardError = true, UseShellExecute = false } };
+            foreach (var arg in new[] { "-a", "-p", Environment.ProcessId.ToString(CultureInfo.InvariantCulture), "-Fnf" })
+                process.StartInfo.ArgumentList.Add(arg);
+            var text = await ReadDescriptorProbeAsync(process, TimeSpan.FromSeconds(5), ct);
+            process.ExitCode.ShouldBe(0);
+            var total = 0;
+            var pki = 0;
+            var descriptor = false;
+            foreach (var line in text.Split('\n'))
+            {
+                if (line.StartsWith('f'))
+                {
+                    descriptor = line.Length > 1 && char.IsDigit(line[1]);
+                    if (descriptor) total++;
+                }
+                else if (descriptor && line.StartsWith('n') && IsWithinRoots(line[1..], canonicalRoots)) pki++;
+            }
+            return (total, pki);
+        }
+        throw new PlatformNotSupportedException("This soak requires Linux procfs or macOS lsof for actual descriptor evidence.");
+    }
+
+    private static async Task<string> ReadDescriptorProbeAsync(Process process, TimeSpan timeout, CancellationToken ct)
+    {
+        using var deadline = CancellationTokenSource.CreateLinkedTokenSource(ct);
+        deadline.CancelAfter(timeout);
+        process.Start();
+        var stdout = process.StandardOutput.ReadToEndAsync(deadline.Token);
+        var stderr = process.StandardError.ReadToEndAsync(deadline.Token);
+        var exited = process.WaitForExitAsync(deadline.Token);
+        try
+        {
+            // Waiting for exit alone does not bound reads: both redirected pipes must also finish.
+            await Task.WhenAll(stdout, stderr, exited).WaitAsync(deadline.Token).ConfigureAwait(false);
+            return await stdout.ConfigureAwait(false);
+        }
+        catch (OperationCanceledException)
+        {
+            try { if (!process.HasExited) process.Kill(entireProcessTree: true); }
+            catch (InvalidOperationException) when (process.HasExited) { /* It exited between the check and kill. */ }
+            await process.WaitForExitAsync(CancellationToken.None).WaitAsync(TimeSpan.FromSeconds(2)).ConfigureAwait(false);
+            // Observe both cancelled drains; never leave a pipe read running after returning.
+            try { await Task.WhenAll(stdout, stderr).WaitAsync(TimeSpan.FromSeconds(2)).ConfigureAwait(false); }
+            catch (OperationCanceledException) { }
+            if (ct.IsCancellationRequested) throw;
+            throw new TimeoutException("Descriptor probe exceeded its process and redirected-stream deadline.");
+        }
+    }
+
+    private static bool IsWithinRoots(string? path, IReadOnlyList<string> roots)
+    {
+        if (path is null || !Path.IsPathFullyQualified(path)) return false;
+        // procfs marks an unlinked but still open file; its containing physical directory still counts.
+        const string deleted = " (deleted)";
+        if (path.EndsWith(deleted, StringComparison.Ordinal)) path = path[..^deleted.Length];
+        var canonical = CanonicalPath(path);
+        return roots.Any(root => canonical.Equals(root, StringComparison.Ordinal)
+            || canonical.StartsWith(Path.EndsInDirectorySeparator(root) ? root : root + Path.DirectorySeparatorChar,
+                StringComparison.Ordinal));
+    }
+
+    internal static string CanonicalPath(string path, int depth = 0)
+    {
+        if (depth > 32) throw new IOException("Descriptor path link resolution exceeded its bound.");
+        var full = Path.GetFullPath(path);
+        var current = Path.GetPathRoot(full)!;
+        foreach (var component in full[current.Length..].Split(Path.DirectorySeparatorChar, StringSplitOptions.RemoveEmptyEntries))
+        {
+            current = Path.Combine(current, component);
+            FileSystemInfo entry = Directory.Exists(current) ? new DirectoryInfo(current) : new FileInfo(current);
+            if (entry.LinkTarget is not null)
+            {
+                var target = entry.ResolveLinkTarget(returnFinalTarget: true)
+                    ?? throw new IOException("Descriptor path link resolution returned no target.");
+                // Resolve parent links too: an alias target can itself begin with /var or /tmp.
+                current = CanonicalPath(target.FullName, depth + 1);
+            }
+        }
+        return Path.TrimEndingDirectorySeparator(current);
+    }
+
+}
diff --git a/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/BaselineRig.cs b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/BaselineRig.cs
new file mode 100644
index 000000000..7508152f3
--- /dev/null
+++ b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/BaselineRig.cs
@@ -0,0 +1,107 @@
+using System.Net;
+using System.Net.Sockets;
+using System.Reflection;
+using Microsoft.Extensions.Logging.Abstractions;
+using Opc.Ua;
+using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
+using ZB.MOM.WW.OtOpcUa.Configuration.Entities;
+using ZB.MOM.WW.OtOpcUa.Configuration.Enums;
+using ZB.MOM.WW.OtOpcUa.Core.Authorization;
+using ZB.MOM.WW.OtOpcUa.OpcUaServer;
+using ZB.MOM.WW.OtOpcUa.OpcUaServer.Security;
+
+internal sealed class BaselineRig : IAsyncDisposable
+{
+    internal const string Cluster = "SITE-A", RawDeviceFolder = "Plant/Modbus/dev1", RawAlarmPath = "Plant/Modbus/dev1/temp_hi";
+    internal const string EqA = "EqA", EqB = "EqB", KeyPrincipal = "event-probe", KeyId = "k-server-events";
+    internal static string KeyPassword => Environment.GetEnvironmentVariable("OTOPCUA_BASELINE_CANONICAL_KEY")
+        ?? throw new InvalidOperationException("An ephemeral fixture credential is required");
+    private readonly OpcUaApplicationHostOptions _options;
+    private OpcUaApplicationHost _host = null!;
+    private bool _disposed;
+    internal OtOpcUaSdkServer Server { get; private set; } = null!;
+    internal OtOpcUaNodeManager Nm => Server.NodeManager!;
+    internal SdkAddressSpaceSink Sink { get; private set; } = null!;
+    internal string EndpointUrl => $"opc.tcp://127.0.0.1:{_options.OpcUaPort}/OtOpcUa";
+    internal string PkiRoot { get; }
+    internal CertificateValidator Validator
+    {
+        get
+        {
+            var applicationField = typeof(OpcUaApplicationHost).GetField("_application", BindingFlags.NonPublic | BindingFlags.Instance)
+                ?? throw new InvalidOperationException("Original host application field is missing");
+            return applicationField.GetValue(_host) is Opc.Ua.Configuration.ApplicationInstance application
+                && application.ApplicationConfiguration.CertificateValidator is CertificateValidator validator ? validator
+                : throw new InvalidOperationException("Original host application field type changed");
+        }
+    }
+    internal BaselineRig(string directory)
+    {
+        PkiRoot = Path.Combine(directory, "server-pki");
+        using var listener = new TcpListener(IPAddress.Loopback, 0);
+        listener.Start();
+        _options = new OpcUaApplicationHostOptions
+        {
+            ApplicationName = "OtOpcUa.SDK2LifecycleSoak", ApplicationUri = $"urn:OtOpcUa.SDK2LifecycleSoak.{Guid.NewGuid():N}",
+            OpcUaPort = ((IPEndPoint)listener.LocalEndpoint).Port, PublicHostname = "127.0.0.1", PkiStoreRoot = PkiRoot,
+            EnabledSecurityProfiles = [OpcUaSecurityProfile.None, OpcUaSecurityProfile.Basic256Sha256SignAndEncrypt],
+            AutoAcceptUntrustedClientCertificates = true,
+        };
+    }
+    internal async Task BootAsync(CancellationToken ct)
+    {
+        Server = new OtOpcUaSdkServer();
+        _host = new OpcUaApplicationHost(_options, NullLogger<OpcUaApplicationHost>.Instance, new Auth());
+        await _host.StartAsync(Server, ct);
+        Canonical.Ledger.Record("host-start");
+        Sink = new SdkAddressSpaceSink(Nm);
+    }
+    internal async Task RestartAsync(CancellationToken ct)
+    {
+        await _host.DisposeAsync();
+        Canonical.Ledger.Record("host-stop");
+        await BootAsync(ct);
+    }
+    internal DataPlaneAuthorityState Enforce(bool enabled, ApiKey[] keys, params NodeAcl[] grants)
+    {
+        var state = new DataPlaneAuthorityState();
+        state.Apply(Cluster, "rev-1", keys, grants, new Dictionary<AclScopeRef, IReadOnlyList<NodeAclPath>>
+        {
+            [new AclScopeRef(NodeAclScopeKind.Equipment, "eq-" + EqA)] = [new NodeAclPath([NodeAclRealms.Uns, EqA])],
+            [new AclScopeRef(NodeAclScopeKind.Equipment, "eq-" + EqB)] = [new NodeAclPath([NodeAclRealms.Uns, EqB])]
+        });
+        Nm.DataPlaneAuthority = state;
+        Nm.Authorizer = new DataPlaneAuthorizer(state, new TriePermissionEvaluator(state.Tries), enabled, NullLogger.Instance, TimeProvider.System);
+        Canonical.Ledger.Record("authority-restore");
+        return state;
+    }
+    internal static ApiKey Key() => new() { ApiKeyId = KeyId, Name = KeyId, SecretHash = "hash", Principal = KeyPrincipal,
+        Enabled = true, CreatedUtc = DateTime.UtcNow.AddDays(-1) };
+    internal static NodeAcl ClusterGrant(string principal, string id, NodePermissions permissions) => new()
+    { NodeAclId = id, ClusterId = Cluster, Principal = principal, ScopeKind = NodeAclScopeKind.Cluster, PermissionFlags = permissions };
+    internal void MaterialiseNative()
+    {
+        Sink.EnsureFolder(RawDeviceFolder, null, "dev1", AddressSpaceRealm.Raw);
+        Sink.MaterialiseAlarmCondition(RawAlarmPath, RawDeviceFolder, "temp_hi", "OffNormalAlarm", 700, AddressSpaceRealm.Raw, isNative: true);
+        Sink.EnsureFolder(EqA, null, "A", AddressSpaceRealm.Uns);
+        Sink.EnsureFolder(EqB, null, "B", AddressSpaceRealm.Uns);
+        Sink.WireAlarmNotifiers(RawAlarmPath, AddressSpaceRealm.Raw, [EqA, EqB], AddressSpaceRealm.Uns);
+    }
+    public async ValueTask DisposeAsync()
+    {
+        if (_disposed) return;
+        _disposed = true;
+        try
+        {
+            if (_host is not null) { await _host.DisposeAsync(); Canonical.Ledger.Record("host-stop"); }
+        }
+        finally { if (Directory.Exists(PkiRoot)) Directory.Delete(PkiRoot, true); }
+    }
+    private sealed class Auth : IOpcUaUserAuthenticator
+    {
+        public Task<OpcUaUserAuthResult> AuthenticateUserNameAsync(string username, string password, CancellationToken ct) =>
+            Task.FromResult(username == "apikey" && password.StartsWith($"otua_{KeyId}_", StringComparison.Ordinal)
+                ? OpcUaUserAuthResult.AllowKey(KeyPrincipal, [OpcUaDataPlaneRoles.AlarmAck, OpcUaDataPlaneRoles.WriteOperate], KeyId)
+                : OpcUaUserAuthResult.Deny("Invalid fixture key"));
+    }
+}
diff --git a/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/CanonicalOperations.cs b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/CanonicalOperations.cs
new file mode 100644
index 000000000..ab34907ea
--- /dev/null
+++ b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/CanonicalOperations.cs
@@ -0,0 +1,244 @@
+using System.Collections.Concurrent;
+using System.Diagnostics;
+using System.Text;
+using Opc.Ua;
+using Opc.Ua.Client;
+using Opc.Ua.Configuration;
+using Shouldly;
+using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
+using ZB.MOM.WW.OtOpcUa.Configuration.Enums;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using ZB.MOM.WW.OtOpcUa.Core.Authorization;
+using ClientSession = Opc.Ua.Client.ISession;
+using Subscription = Opc.Ua.Client.Subscription;
+using MonitoredItem = Opc.Ua.Client.MonitoredItem;
+internal static partial class Canonical
+{
+    internal static (int Browse, int History) ClosedListObservation;
+    private static void Configure(BaselineRig rig)
+    {
+        Ledger.Record("configure");
+        rig.MaterialiseNative();
+        rig.Nm.HistorianDataSource = new SqlLikeEventSource(Enumerable.Range(0, 40)
+            .Select(i => new HistoricalEvent($"soak-{i}", "source", Epoch.AddSeconds(i), Epoch, "soak", 500)).ToList());
+        rig.Nm.NodeWriteGateway = new AcceptWrites();
+        MaterialiseValues(rig);
+        rig.Enforce(true, [BaselineRig.Key()], Grant());
+    }
+
+    private static ZB.MOM.WW.OtOpcUa.Configuration.Entities.NodeAcl Grant() => BaselineRig.ClusterGrant(
+        BaselineRig.KeyPrincipal, "soak-grant", NodePermissions.Browse | NodePermissions.Read | NodePermissions.Subscribe
+            | NodePermissions.WriteOperate | NodePermissions.HistoryRead);
+
+    private static void MaterialiseValues(BaselineRig rig)
+    {
+        rig.Sink.EnsureFolder(BaselineRig.RawDeviceFolder, null, "Device", AddressSpaceRealm.Raw);
+        rig.Sink.EnsureVariable(Scalar, BaselineRig.RawDeviceFolder, "Scalar", "Int32", true, AddressSpaceRealm.Raw);
+        rig.Sink.EnsureVariable(ArrayTag, BaselineRig.RawDeviceFolder, "Array", "Int16", true, AddressSpaceRealm.Raw,
+            isArray: true, arrayLength: 4);
+        rig.Sink.EnsureFolder("SoakEquipment", null, "Equipment", AddressSpaceRealm.Uns);
+        rig.Sink.EnsureVariable(UnsScalar, "SoakEquipment", "Scalar", "Int32", true, AddressSpaceRealm.Uns);
+        for (var i = 0; i < 16; i++) rig.Sink.EnsureVariable($"{BaselineRig.RawDeviceFolder}/Browse{i}",
+            BaselineRig.RawDeviceFolder, $"Browse{i}", "Int32", false, AddressSpaceRealm.Raw);
+        rig.Sink.WriteValue(Scalar, 0, OpcUaStatus.Good, DateTime.UtcNow, AddressSpaceRealm.Raw);
+        rig.Sink.WriteValue(ArrayTag, new short[] { 0, 1, 2, 3 }, OpcUaStatus.Good, DateTime.UtcNow, AddressSpaceRealm.Raw);
+        rig.Sink.WriteValue(UnsScalar, 0, OpcUaStatus.Good, DateTime.UtcNow, AddressSpaceRealm.Uns);
+    }
+
+    private static async Task ExerciseAsync(BaselineRig rig, ApplicationConfiguration config, int cycle,
+        StreamWriter evidence, CancellationToken ct)
+    {
+        await using var proxy = new PauseProxy(new Uri(rig.EndpointUrl).Port);
+        using var owner = await ConnectAsync(rig, config, proxy.Port, ct);
+        using var other = await ConnectAsync(rig, config, null, ct);
+        var ownedSessions = rig.Server.CurrentInstance.SessionManager.GetSessions().ToArray();
+        ownedSessions.Length.ShouldBe(2);
+        var scalar = Raw(owner, Scalar);
+        var array = Raw(owner, ArrayTag);
+        var unsNs = owner.NamespaceUris.GetIndex(V3NodeIds.UnsNamespaceUri);
+        unsNs.ShouldBeGreaterThan(0);
+        var uns = new NodeId(UnsScalar, (ushort)unsNs);
+        owner.NamespaceUris.GetString(scalar.NamespaceIndex).ShouldBe(V3NodeIds.RawNamespaceUri);
+        owner.NamespaceUris.GetString(uns.NamespaceIndex).ShouldBe(V3NodeIds.UnsNamespaceUri);
+        using var subscription = new Subscription(owner.DefaultSubscription) { PublishingInterval = 100, KeepAliveCount = 10 };
+        owner.AddSubscription(subscription);
+        try
+        {
+            await Ledger.Call("subscription-create", () => subscription.CreateAsync(ct));
+            var seen = new ConcurrentDictionary<NodeId, Variant>();
+            foreach (var id in new[] { scalar, array, uns })
+            {
+                var item = new MonitoredItem(subscription.DefaultItem) { StartNodeId = id, AttributeId = Attributes.Value,
+                    SamplingInterval = 50, QueueSize = 10 };
+                item.Notification += (sender, _) =>
+                {
+                    foreach (var value in sender.DequeueValues()) if (StatusCode.IsGood(value.StatusCode)) seen[id] = value.WrappedValue;
+                };
+                subscription.AddItem(item);
+            }
+            await Ledger.Call("subscription-apply", () => subscription.ApplyChangesAsync(ct));
+            subscription.MonitoredItems.ShouldAllBe(item => ServiceResult.IsGood(item.Status.Error));
+            PublicCounts(rig).ShouldBe((2, 1, 3));
+            var values = new short[] { (short)(cycle % 30000), 2, 3, 4 };
+            var writes = await Ledger.Call("write", () => owner.WriteAsync(null, new[]
+            {
+                new WriteValue { NodeId = scalar, AttributeId = Attributes.Value, Value = new DataValue(new Variant(cycle)) },
+                new WriteValue { NodeId = array, AttributeId = Attributes.Value, Value = new DataValue(new Variant(values)) },
+                new WriteValue { NodeId = uns, AttributeId = Attributes.Value, Value = new DataValue(new Variant(cycle)) },
+            }, ct));
+            writes.Results.ToList().ShouldAllBe(status => status == StatusCodes.Good);
+            (await Ledger.Call("read-value", () => owner.ReadValueAsync(scalar, ct))).Value.ShouldBeOfType<int>().ShouldBe(cycle);
+            (await Ledger.Call("read-value", () => owner.ReadValueAsync(array, ct))).Value.ShouldBeOfType<short[]>().ShouldBe(values);
+            (await Ledger.Call("read-value", () => owner.ReadValueAsync(uns, ct))).Value.ShouldBeOfType<int>().ShouldBe(cycle);
+            await EventuallyAsync(() => seen.TryGetValue(scalar, out var value) && ScalarValue(value) == cycle
+                && seen.ContainsKey(array) && seen.TryGetValue(uns, out var mirror) && ScalarValue(mirror) == cycle, ct);
+
+            // One explicitly released and one deliberately abandoned browse point.
+            var browse = await BrowseAsync(owner, ct);
+            RequirePoint(browse);
+            (await Ledger.Call("browse-next", () => owner.BrowseNextAsync(null, true, [browse], ct))).Results[0].StatusCode.ShouldBe(StatusCodes.Good);
+            RequirePoint(await BrowseAsync(owner, ct));
+            // Production history points: cross-session denial, single-use resume, explicit release and close cleanup.
+            var first = (await PageAsync(owner, default, false, ct)).ContinuationPoint;
+            RequirePoint(first);
+            (await PageAsync(other, first, false, ct)).StatusCode.ShouldBe(StatusCodes.BadContinuationPointInvalid);
+            var next = (await PageAsync(owner, first, false, ct)).ContinuationPoint;
+            RequirePoint(next);
+            (await PageAsync(owner, next, true, ct)).StatusCode.ShouldBe(StatusCodes.Good);
+            for (var i = 0; i < 6; i++) RequirePoint((await PageAsync(owner, default, false, ct)).ContinuationPoint);
+            var held = ownedSessions.Select(ContinuationCounts).ToArray();
+            held.Sum(count => count.Browse).ShouldBeGreaterThan(0);
+            held.Sum(count => count.History).ShouldBeGreaterThan(0);
+            var active = PublicCounts(rig);
+            await LogAsync(evidence, new { kind = "active", cycle, sessions = active.Sessions,
+                subscriptions = active.Subscriptions, items = active.Items, browsePoints = held.Sum(x => x.Browse), historyPoints = held.Sum(x => x.History) });
+
+            rig.Nm.UpdateTagAttributes(Scalar, false, null, "Int32", false, null, AddressSpaceRealm.Raw).ShouldBeTrue();
+            Ledger.Record("writable-off");
+            rig.Nm.UpdateTagAttributes(Scalar, true, null, "Int32", false, null, AddressSpaceRealm.Raw).ShouldBeTrue();
+            Ledger.Record("writable-on");
+            rig.Nm.RemoveVariableNode(ArrayTag, AddressSpaceRealm.Raw).ShouldBeTrue();
+            Ledger.Record("variable-remove");
+            rig.Sink.EnsureVariable(ArrayTag, BaselineRig.RawDeviceFolder, "Array", "Int16", true, AddressSpaceRealm.Raw,
+                isArray: true, arrayLength: 4);
+            rig.Sink.WriteValue(ArrayTag, values, OpcUaStatus.Good, DateTime.UtcNow, AddressSpaceRealm.Raw);
+            var authority = rig.Nm.DataPlaneAuthority.ShouldBeOfType<DataPlaneAuthorityState>();
+            Ledger.Record("key-revoke");
+            authority.Apply(BaselineRig.Cluster, $"revoked-{cycle}", [], [Grant()],
+                new Dictionary<AclScopeRef, IReadOnlyList<NodeAclPath>>());
+            var denied = await Ledger.Call("read-service", () => owner.ReadAsync(null, 0, TimestampsToReturn.Neither,
+                [new ReadValueId { NodeId = scalar, AttributeId = Attributes.Value }], ct));
+            denied.Results[0].StatusCode.ShouldBe(StatusCodes.BadUserAccessDenied);
+            rig.Enforce(true, [BaselineRig.Key()], Grant());
+
+            proxy.Pause();
+            Ledger.Record("network-pause");
+            var stalled = Stopwatch.StartNew();
+            string stalledStatus;
+            try
+            {
+                using var timeout = CancellationTokenSource.CreateLinkedTokenSource(ct);
+                timeout.CancelAfter(TimeSpan.FromSeconds(1));
+                await Ledger.Call("read-value", () => owner.ReadValueAsync(scalar, timeout.Token)).WaitAsync(TimeSpan.FromSeconds(5), ct);
+                throw new InvalidOperationException("The deliberately paused network unexpectedly completed the read.");
+            }
+            catch (OperationCanceledException) when (!ct.IsCancellationRequested) { stalledStatus = "OperationCanceled"; }
+            // Exact-tag ChannelAsyncOperation maps a canceled completion waiter to BadRequestInterrupted.
+            catch (ServiceResultException error) when (error.StatusCode == StatusCodes.BadTimeout
+                || error.StatusCode == StatusCodes.BadRequestCancelledByClient || error.StatusCode == StatusCodes.BadRequestTimeout
+                || error.StatusCode == StatusCodes.BadRequestInterrupted) { stalledStatus = error.StatusCode.ToString(); }
+            finally { proxy.Resume(); }
+            (await Ledger.Call("read-value", () => owner.ReadValueAsync(scalar, ct))).StatusCode.ShouldBe(StatusCodes.Good);
+            await LogAsync(evidence, new { kind = "network-stall-recovered", cycle, status = stalledStatus, seconds = stalled.Elapsed.TotalSeconds });
+            await Ledger.Call("subscription-delete", () => subscription.DeleteAsync(true, ct));
+            await Ledger.Call("subscription-remove", () => owner.RemoveSubscriptionAsync(subscription, ct));
+            rig.Sink.RebuildAddressSpace();
+            Ledger.Record("address-space-rebuild");
+            Configure(rig);
+            Ledger.Record("cycle-wire-body-completed");
+        }
+        finally
+        {
+            proxy.Resume();
+            await Ledger.Call("session-close", () => owner.CloseAsync(ct)).WaitAsync(TimeSpan.FromSeconds(10), ct);
+            await Ledger.Call("session-close", () => other.CloseAsync(ct)).WaitAsync(TimeSpan.FromSeconds(10), ct);
+            // Comparator (lmxopcua#799): the held-reference zero-closed-list comparison is an SDK2-only contract. SDK 1.5's
+            // Session.Close keeps its lists until Dispose (baseline-canonical/README.md, OWNERSHIP.md: closed sessions and
+            // points are collected once harness roots drop). Record the counts each cycle instead of asserting; the session
+            // must still leave the SessionManager, which the loop's quiescent zero-checks assert.
+            var retained = ownedSessions.Select(ContinuationCounts).ToArray();
+            ClosedListObservation = (retained.Sum(x => x.Browse), retained.Sum(x => x.History));
+        }
+    }
+
+    private static async Task RestartWithActiveResourcesAsync(BaselineRig rig, ApplicationConfiguration config,
+        CancellationToken ct)
+    {
+        using var client = await ConnectAsync(rig, config, null, ct);
+        using var subscription = new Subscription(client.DefaultSubscription) { PublishingInterval = 100 };
+        client.AddSubscription(subscription);
+        await Ledger.Call("subscription-create", () => subscription.CreateAsync(ct));
+        subscription.AddItem(new MonitoredItem(subscription.DefaultItem)
+        {
+            StartNodeId = Raw(client, Scalar), AttributeId = Attributes.Value, SamplingInterval = 50,
+        });
+        await Ledger.Call("subscription-apply", () => subscription.ApplyChangesAsync(ct));
+        PublicCounts(rig).ShouldBe((1, 1, 1));
+        RequirePoint(await BrowseAsync(client, ct));
+        RequirePoint((await PageAsync(client, default, false, ct)).ContinuationPoint);
+        var oldInternal = rig.Server.CurrentInstance;
+        var oldSessionManager = oldInternal.SessionManager;
+        var oldSubscriptionManager = oldInternal.SubscriptionManager;
+        var oldSessions = oldSessionManager.GetSessions().ToArray();
+        var oldSubscriptions = oldSubscriptionManager.GetSubscriptions().ToArray();
+        var oldValidator = rig.Validator;
+        var oldStores = BaselineMetrics.CachedStoreReferences(oldValidator);
+        await rig.RestartAsync(ct).WaitAsync(TimeSpan.FromSeconds(20), ct);
+        oldSessionManager.GetSessions().ShouldBeEmpty();
+        oldSubscriptionManager.GetSubscriptions().ShouldBeEmpty();
+        oldSubscriptions.ShouldAllBe(item => item.MonitoredItemCount == 0);
+        foreach (var session in oldSessions) ContinuationCounts(session).ShouldBe((0, 0));
+        await LogAsync(CurrentEvidence, new { kind = "original-validator-after-stop", cachedStoreReferencesBefore = oldStores,
+            cachedStoreReferencesAfter = BaselineMetrics.CachedStoreReferences(oldValidator),
+            disposalFlagObservable = false, reason = "SDK1.5 has no CertificateManager disposal API or disposed flag" });
+        PublicCounts(rig).ShouldBe((0, 0, 0));
+    }
+
+    private static async Task<ClientSession> ConnectAsync(BaselineRig rig, ApplicationConfiguration config,
+        int? proxyPort, CancellationToken ct)
+    {
+        var telemetry = DefaultTelemetry.Create(_ => { });
+        var endpoint = await CoreClientUtils.SelectEndpointAsync(config, rig.EndpointUrl, true, telemetry, ct)
+            ?? throw new InvalidOperationException("No encrypted endpoint.");
+        endpoint.SecurityMode.ShouldBe(MessageSecurityMode.SignAndEncrypt);
+        if (proxyPort is { } port) endpoint.EndpointUrl = $"opc.tcp://127.0.0.1:{port}/OtOpcUa";
+        return await Ledger.Call("session-create", () => new DefaultSessionFactory(telemetry).CreateAsync(config,
+            new ConfiguredEndpoint(null, endpoint, EndpointConfiguration.Create(config)), false, false,
+            "SDK2LifecycleSoak", 15_000, new UserIdentity("apikey", Encoding.UTF8.GetBytes(BaselineRig.KeyPassword)), default, ct));
+    }
+
+    private static NodeId Raw(ClientSession session, string id)
+    {
+        var ns = session.NamespaceUris.GetIndex(V3NodeIds.RawNamespaceUri);
+        ns.ShouldBeGreaterThan(0);
+        return new NodeId(id, (ushort)ns);
+    }
+
+    private static async Task<byte[]?> BrowseAsync(ClientSession session, CancellationToken ct) =>
+        (await Ledger.Call("browse", () => session.BrowseAsync(null, null, 1, [new BrowseDescription
+        {
+            NodeId = Raw(session, BaselineRig.RawDeviceFolder), BrowseDirection = BrowseDirection.Forward,
+            ReferenceTypeId = ReferenceTypeIds.HierarchicalReferences, IncludeSubtypes = true,
+            ResultMask = (uint)BrowseResultMask.All,
+        }], ct))).Results[0].ContinuationPoint;
+
+    private static async Task<Opc.Ua.HistoryReadResult> PageAsync(ClientSession session, byte[]? point,
+        bool release, CancellationToken ct) => (await Ledger.Call("history-read", () => session.HistoryReadAsync(null, new ExtensionObject(new ReadEventDetails
+        {
+            StartTime = Epoch.AddDays(-1), EndTime = Epoch.AddDays(1), NumValuesPerNode = 4,
+            Filter = new EventFilter { SelectClauses = [new SimpleAttributeOperand(ObjectTypeIds.BaseEventType,
+                new QualifiedName(BrowseNames.EventId))] },
+        }), TimestampsToReturn.Both, release,
+        [new HistoryReadValueId { NodeId = Raw(session, BaselineRig.RawDeviceFolder), ContinuationPoint = point }], ct))).Results[0];
+
+}
diff --git a/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/Program.cs b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/Program.cs
new file mode 100644
index 000000000..ed7f54b11
--- /dev/null
+++ b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/Program.cs
@@ -0,0 +1,318 @@
+using System.Collections.Concurrent;
+using System.Diagnostics;
+using System.Net;
+using System.Net.Sockets;
+using System.Reflection;
+using System.Runtime.InteropServices;
+using System.Text.Json;
+using Opc.Ua;
+using Opc.Ua.Configuration;
+using Opc.Ua.Server;
+using Shouldly;
+using ZB.MOM.WW.OtOpcUa.Commons.OpcUa;
+using ZB.MOM.WW.OtOpcUa.Core.Abstractions;
+using CoreHistoryReadResult = ZB.MOM.WW.OtOpcUa.Core.Abstractions.HistoryReadResult;
+return await Canonical.ComparatorAsync(args);
+internal static partial class Canonical
+{
+    private const string Scalar = BaselineRig.RawDeviceFolder + "/SoakScalar";
+    private const string ArrayTag = BaselineRig.RawDeviceFolder + "/SoakArray";
+    private const string UnsScalar = "SoakEquipment/Scalar";
+    private static readonly DateTime Epoch = new(2026,10,1,0,0,0,DateTimeKind.Utc);
+    internal static readonly OperationLedger Ledger = new();
+    private static StreamWriter CurrentEvidence = null!;
+
+    /// <summary>
+    ///     lmxopcua#799 SDK 1.5.378.182 comparator: the canonical late-slope loop (same cycle body, same every-fourth-cycle
+    ///     active restart, same quiescent sample after each cycle, same cycle-3 cold baseline and caps with a latched first
+    ///     rejection, same 30 s cycle / 25 s restart / 120 s startup bounds, same 7,200 s phase) driven against the immutable
+    ///     efb9197a SDK1 publication. Comparator only: acceptance=false. Differences from the SDK2 test are listed in
+    ///     README.md (standalone process instead of the VSTest testhost; no SDK2 certificate-manager disposal observables;
+    ///     closed-session continuation lists recorded rather than asserted; managed-monotonic guard latched, not fatal).
+    /// </summary>
+    internal static async Task<int> ComparatorAsync(string[] args)
+    {
+        if (args.Length != 3 || args[2] != "--comparator") throw new InvalidOperationException("Usage: <fresh-output> 7200 --comparator");
+        var root = Path.GetFullPath(args[0]); var seconds = int.Parse(args[1]);
+        // The measured phase matches the 7200 s late-slope run; a 60 s smoke exists only to qualify the tooling (never a result).
+        if (seconds != 7200 && !(seconds == 60 && Environment.GetEnvironmentVariable("OTOPCUA_COMPARATOR_SMOKE") == "1"))
+            throw new InvalidOperationException("The comparator phase matches the 7200 s late-slope run");
+        if (Directory.Exists(root)) throw new InvalidOperationException("Use a fresh private artifact directory");
+        Directory.CreateDirectory(root);
+        await using var output = new StreamWriter(new FileStream(Path.Combine(root, "resources.jsonl"), FileMode.CreateNew, FileAccess.Write, FileShare.Read));
+        CurrentEvidence = output;
+        var sdk = typeof(NodeId).Assembly.GetCustomAttribute<AssemblyInformationalVersionAttribute>()?.InformationalVersion;
+        if (sdk is null || !sdk.StartsWith("1.5.378.182+", StringComparison.Ordinal)) throw new InvalidOperationException("The immutable .182 SDK is required");
+        var clientRoot = Path.Combine(root, "private-fixture", "client-pki");
+        var startup = Stopwatch.StartNew();
+        using var startupDeadline = new CancellationTokenSource(TimeSpan.FromSeconds(120));
+        var telemetry = DefaultTelemetry.Create(_ => { });
+        var config = new ApplicationConfiguration(telemetry)
+        {
+            ApplicationName = "SDK2LifecycleSoak", ApplicationUri = $"urn:SDK2LifecycleSoak:{Guid.NewGuid():N}", ApplicationType = ApplicationType.Client,
+            SecurityConfiguration = new SecurityConfiguration
+            {
+                ApplicationCertificate = new CertificateIdentifier { StoreType = CertificateStoreType.Directory, StorePath = Path.Combine(clientRoot, "own"), SubjectName = "CN=SDK2LifecycleSoak" },
+                TrustedIssuerCertificates = new CertificateTrustList { StoreType = CertificateStoreType.Directory, StorePath = Path.Combine(clientRoot, "issuer") },
+                TrustedPeerCertificates = new CertificateTrustList { StoreType = CertificateStoreType.Directory, StorePath = Path.Combine(clientRoot, "trusted") },
+                RejectedCertificateStore = new CertificateTrustList { StoreType = CertificateStoreType.Directory, StorePath = Path.Combine(clientRoot, "rejected") }, AutoAcceptUntrustedCertificates = true
+            },
+            ClientConfiguration = new ClientConfiguration { DefaultSessionTimeout = 15000 }, TransportQuotas = new TransportQuotas { OperationTimeout = 5000 }
+        };
+        var application = new ApplicationInstance(telemetry) { ApplicationConfiguration = config };
+        await config.ValidateAsync(ApplicationType.Client, startupDeadline.Token);
+        await application.CheckApplicationInstanceCertificatesAsync(true, null, startupDeadline.Token);
+        var rig = new BaselineRig(Path.Combine(root, "private-fixture"));
+        await rig.BootAsync(startupDeadline.Token); Configure(rig);
+        var startupSeconds = startup.Elapsed.TotalSeconds;
+        var watch = Stopwatch.StartNew();
+        await LogAsync(output, new
+        {
+            kind = "start", utc = DateTimeOffset.UtcNow, processId = Environment.ProcessId, mode = "sdk1-comparator", requestedSeconds = seconds,
+            build = Environment.GetEnvironmentVariable("OTOPCUA_COMPARATOR_SOURCE"), sourcePublication = "efb9197a", sdk,
+            runtime = Environment.Version.ToString(), architecture = RuntimeInformation.ProcessArchitecture.ToString(), startupSeconds,
+            limits = new { retainedManagedGrowthBytes = 64L << 20, rssGrowthBytes = 128L << 20, fdGrowth = 32 }, acceptance = false,
+            unsupportedObservables = new[] { "SDK2 CertificateManager disposed flag", "SDK2 manager-owned cache-clear proof", "ApplicationInstance.DisposeAsync" },
+        });
+        var cycles = 0; var restarts = 0; var lastCompleted = 0d;
+        Dictionary<string, object>? baseline = null; object? firstRejection = null; object? monotonicRejection = null;
+        var retained = new Queue<long>();
+        var failures = new List<string>();
+        try
+        {
+            while (lastCompleted < seconds)
+            {
+                var cycle = Stopwatch.StartNew();
+                using var cycleDeadline = new CancellationTokenSource(TimeSpan.FromSeconds(30));
+                var ct = cycleDeadline.Token;
+                await ExerciseAsync(rig, config, ++cycles, output, ct);
+                await EventuallyAsync(() => PublicCounts(rig) == (0, 0, 0), ct);
+                var sample = await CaptureAsync(rig, config, cycles, watch.Elapsed.TotalSeconds, clientRoot, ct);
+                await LogAsync(output, new { kind = "resource-observation", resources = sample });
+                foreach (var zero in new[] { "Sessions", "Subscriptions", "Items", "BrowsePoints", "HistoryPoints", "LiveDataItems", "LiveEventItems", "MonitoredNodes", "PkiDescriptors" })
+                    Convert.ToInt64(sample[zero]).ShouldBe(0, $"quiescent {zero} must be zero");
+                if (cycles >= 3)
+                {
+                    baseline ??= sample;
+                    foreach (var steady in new[] { "Variables", "Folders", "Conditions", "ServerCachedStoreReferences", "ClientCachedStoreReferences" })
+                        sample[steady].ShouldBe(baseline[steady], $"quiescent {steady} must stay at its cycle-3 value");
+                    var exceeded = new List<string>();
+                    if ((int)sample["Descriptors"] > (int)baseline["Descriptors"] + 32) exceeded.Add("Descriptors");
+                    if ((long)sample["ManagedBytes"] > (long)baseline["ManagedBytes"] + (64L << 20)) exceeded.Add("ManagedBytes");
+                    if ((long)sample["RssBytes"] > (long)baseline["RssBytes"] + (128L << 20)) exceeded.Add("RssBytes");
+                    if (exceeded.Count > 0 && firstRejection is null)
+                    {
+                        firstRejection = new { cycle = cycles, seconds = watch.Elapsed.TotalSeconds, exceededFields = exceeded, resources = sample, baseline };
+                        await LogAsync(output, new { kind = "budget-rejected", cycle = cycles, seconds = watch.Elapsed.TotalSeconds, exceededFields = exceeded, resources = sample, baseline });
+                    }
+                    retained.Enqueue((long)sample["ManagedBytes"]);
+                    if (retained.Count > 24) retained.Dequeue();
+                    var window = retained.ToArray();
+                    if (window.Length == 24 && monotonicRejection is null && window.Zip(window.Skip(1)).All(p => p.Second > p.First) && window[^1] - window[0] > (16L << 20))
+                    {
+                        monotonicRejection = new { cycle = cycles, seconds = watch.Elapsed.TotalSeconds, first = window[0], last = window[^1] };
+                        await LogAsync(output, new { kind = "managed-monotonic-rejected", cycle = cycles, seconds = watch.Elapsed.TotalSeconds, first = window[0], last = window[^1] });
+                    }
+                }
+                await LogAsync(output, new { kind = firstRejection is null ? "quiescent" : "quiescent-budget-rejected", cycleSeconds = cycle.Elapsed.TotalSeconds,
+                    closedSessionPointsWhileHeld = new { browse = ClosedListObservation.Browse, history = ClosedListObservation.History }, resources = sample });
+                if (cycles % 4 == 0)
+                {
+                    var restart = Stopwatch.StartNew();
+                    using var restartDeadline = CancellationTokenSource.CreateLinkedTokenSource(ct);
+                    restartDeadline.CancelAfter(TimeSpan.FromSeconds(25));
+                    await RestartWithActiveResourcesAsync(rig, config, restartDeadline.Token);
+                    restartDeadline.Token.ThrowIfCancellationRequested();
+                    var bounded = restart.Elapsed.TotalSeconds;
+                    bounded.ShouldBeLessThanOrEqualTo(25);
+                    Configure(rig); restarts++;
+                    await LogAsync(output, new { kind = "restart", cycles, restarts, seconds = restart.Elapsed.TotalSeconds, boundedRestartSeconds = bounded });
+                }
+                ct.ThrowIfCancellationRequested();
+                cycle.Elapsed.TotalSeconds.ShouldBeLessThanOrEqualTo(30);
+                lastCompleted = watch.Elapsed.TotalSeconds;
+                await LogAsync(output, new { kind = "comparator-cycle", cycle = cycles, restarts, elapsedSeconds = lastCompleted, cycleSeconds = cycle.Elapsed.TotalSeconds });
+            }
+        }
+        catch (Exception error)
+        {
+            failures.Add(error.GetType().FullName!);
+            await LogAsync(output, new { kind = "failed", cycles, restarts, seconds = watch.Elapsed.TotalSeconds, exceptionType = error.GetType().FullName,
+                message = error.Message.Length > 600 ? error.Message[..600] : error.Message,
+                uaStatus = error is ServiceResultException ua ? ua.StatusCode.ToString() : null, ledger = Ledger.Snapshot() });
+            Console.Error.WriteLine(error);
+        }
+        var phaseSeconds = watch.Elapsed.TotalSeconds;
+        var shutdown = Stopwatch.StartNew();
+        var shutdownVerified = false;
+        try
+        {
+            await rig.DisposeAsync().AsTask().WaitAsync(TimeSpan.FromSeconds(20));
+            await Task.Run(() => { if (Directory.Exists(clientRoot)) Directory.Delete(clientRoot, true); }).WaitAsync(TimeSpan.FromSeconds(5));
+            using var probe = new CancellationTokenSource(TimeSpan.FromSeconds(10));
+            (await BaselineMetrics.DescriptorsAsync(probe.Token, clientRoot, rig.PkiRoot)).Pki.ShouldBe(0);
+            Directory.Exists(clientRoot).ShouldBeFalse(); Directory.Exists(rig.PkiRoot).ShouldBeFalse();
+            shutdownVerified = shutdown.Elapsed.TotalSeconds <= 60;
+        }
+        catch (Exception error) { failures.Add("shutdown:" + error.GetType().FullName); Console.Error.WriteLine(error); }
+        await LogAsync(output, new
+        {
+            kind = "comparator-result", mode = "sdk1-comparator", cycles, restarts, cycleSeconds = phaseSeconds, shutdownSeconds = shutdown.Elapsed.TotalSeconds,
+            durationCompleted = lastCompleted >= seconds && failures.Count == 0, shutdownVerified, coldBudgetRejected = firstRejection is not null,
+            firstRejection, managedMonotonicRejected = monotonicRejection, fatalFailure = failures.Count != 0, failureTypes = failures,
+            applicationInstanceDisposal = "unsupported on SDK 1.5 (no DisposeAsync)", ledger = Ledger.Snapshot(), acceptance = false,
+        });
+        return failures.Count != 0 ? 1 : firstRejection is not null || monotonicRejection is not null ? 3 : 0;
+    }
+
+    private static async Task<Dictionary<string, object>> CaptureAsync(BaselineRig rig, ApplicationConfiguration config, int cycle, double seconds,
+        string clientRoot, CancellationToken ct)
+    {
+        var counts = PublicCounts(rig);
+        var points = rig.Server.CurrentInstance.SessionManager.GetSessions().Select(ContinuationCounts).ToArray();
+        var descriptors = await BaselineMetrics.DescriptorsAsync(ct, clientRoot, rig.PkiRoot);
+        var retainedBytes = GC.GetTotalMemory(forceFullCollection: true);
+        var memory = GC.GetGCMemoryInfo();
+        using var process = Process.GetCurrentProcess();
+        process.Refresh();
+        return new Dictionary<string, object>
+        {
+            ["Cycle"] = cycle, ["Seconds"] = seconds, ["Sessions"] = counts.Sessions, ["Subscriptions"] = counts.Subscriptions, ["Items"] = counts.Items,
+            ["BrowsePoints"] = points.Sum(x => x.Browse), ["HistoryPoints"] = points.Sum(x => x.History),
+            ["LiveDataItems"] = BaselineMetrics.Counter(rig.Nm, "LiveItemCount"), ["LiveEventItems"] = BaselineMetrics.Counter(rig.Nm, "LiveEventItemCount"),
+            ["MonitoredNodes"] = BaselineMetrics.Counter(rig.Nm, "MonitoredNodeCount"), ["Variables"] = OptionalCounter(rig.Nm, "VariableCount"),
+            ["Folders"] = OptionalCounter(rig.Nm, "FolderCount"), ["Conditions"] = OptionalCounter(rig.Nm, "AlarmConditionCount"),
+            ["ServerCachedStoreReferences"] = BaselineMetrics.CachedStoreReferences(rig.Validator),
+            ["ClientCachedStoreReferences"] = BaselineMetrics.CachedStoreReferences(config.CertificateValidator),
+            ["Descriptors"] = descriptors.Total, ["PkiDescriptors"] = descriptors.Pki, ["ManagedBytes"] = retainedBytes, ["RssBytes"] = process.WorkingSet64,
+            ["PrivateBytes"] = process.PrivateMemorySize64, ["AllocatedBytes"] = GC.GetTotalAllocatedBytes(),
+            ["Gen0"] = GC.CollectionCount(0), ["Gen1"] = GC.CollectionCount(1), ["Gen2"] = GC.CollectionCount(2), ["GcCommittedBytes"] = memory.TotalCommittedBytes,
+            ["GcHeapBytes"] = memory.HeapSizeBytes, ["GcFragmentedBytes"] = memory.FragmentedBytes, ["PinnedObjects"] = memory.PinnedObjectsCount,
+            ["PendingFinalizers"] = memory.FinalizationPendingCount, ["JitMethods"] = System.Runtime.JitInfo.GetCompiledMethodCount(),
+            ["JitIlBytes"] = System.Runtime.JitInfo.GetCompiledILBytes(), ["ActiveTimers"] = Timer.ActiveCount, ["Threads"] = process.Threads.Count,
+        };
+    }
+
+    private static int OptionalCounter(object manager, string name) =>
+        manager.GetType().GetProperty(name, BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)?.GetValue(manager) is int value ? value : -1;
+
+    private static int ScalarValue(Variant value)=>value.Value is int result?result:throw new InvalidOperationException("Expected scalar Int32 CLR shape");
+    private static void RequirePoint(byte[]? point)=>(point is {Length:>0}).ShouldBeTrue();
+    private static (int Browse,int History) ContinuationCounts(ISession session)=>BaselineMetrics.Points(session);
+    private static (int Sessions,int Subscriptions,int Items) PublicCounts(BaselineRig rig)
+    {var subscriptions=rig.Server.CurrentInstance.SubscriptionManager.GetSubscriptions();return(rig.Server.CurrentInstance.SessionManager.GetSessions().Count,subscriptions.Count,subscriptions.Sum(s=>s.MonitoredItemCount));}
+    private static async Task EventuallyAsync(Func<bool> condition,CancellationToken ct)
+    {var elapsed=Stopwatch.StartNew();while(!condition()&&elapsed.Elapsed<TimeSpan.FromSeconds(10))await Task.Delay(25,ct);condition().ShouldBeTrue();}
+    private static async Task LogAsync(StreamWriter output,object value){await output.WriteLineAsync(JsonSerializer.Serialize(value));await output.FlushAsync();}
+    private sealed class AcceptWrites:IOpcUaNodeWriteGateway
+    {public Task<NodeWriteOutcome> WriteAsync(string id,object? value,AddressSpaceRealm realm,CancellationToken ct)=>Task.FromResult(new NodeWriteOutcome(true,null));}
+    internal sealed class SqlLikeEventSource(List<HistoricalEvent> events) : IHistorianDataSource
+    {
+        private int _eventReads;
+        internal int EventReads => Volatile.Read(ref _eventReads);
+        private readonly List<HistoricalEvent> _all =
+            events.OrderBy(e => e.EventTimeUtc).ThenBy(e => e.EventId, StringComparer.Ordinal).ToList();
+
+        public async Task<HistoricalEventsResult> ReadEventsAsync(
+            string? sourceName, DateTime startUtc, DateTime endUtc, int maxEvents, CancellationToken ct)
+        {
+            Interlocked.Increment(ref _eventReads);
+            await Task.Delay(1, ct).ConfigureAwait(false); // complete on a pool thread, like a real backend
+            var window = _all.Where(e => e.EventTimeUtc >= startUtc && e.EventTimeUtc < endUtc).ToList();
+            var cap = maxEvents <= 0 ? 1000 : maxEvents;
+            return new HistoricalEventsResult(window.Take(cap).ToList(), window.Count > cap ? new byte[] { 1 } : null);
+        }
+
+        public bool SupportsReverseEvents => true;
+
+        /// <summary>The #675 overload: reverse is <c>(lo, hi]</c> by (time, id) descending.</summary>
+        public async Task<HistoricalEventsResult> ReadEventsAsync(
+            string? sourceName, DateTime startUtc, DateTime endUtc, int maxEvents, bool reverse, CancellationToken ct)
+        {
+            if (!reverse) return await ReadEventsAsync(sourceName, startUtc, endUtc, maxEvents, ct).ConfigureAwait(false);
+            await Task.Delay(1, ct).ConfigureAwait(false);
+            var (lo, hi) = startUtc <= endUtc ? (startUtc, endUtc) : (endUtc, startUtc);
+            var window = _all.Where(e => e.EventTimeUtc > lo && e.EventTimeUtc <= hi).Reverse().ToList();
+            var cap = maxEvents <= 0 ? 1000 : maxEvents;
+            return new HistoricalEventsResult(window.Take(cap).ToList(), window.Count > cap ? new byte[] { 1 } : null);
+        }
+
+        public Task<CoreHistoryReadResult> ReadRawAsync(string r, DateTime s, DateTime e, uint m, CancellationToken ct) =>
+            NullHistorianDataSource.Instance.ReadRawAsync(r, s, e, m, ct);
+        public Task<CoreHistoryReadResult> ReadProcessedAsync(
+            string r, DateTime s, DateTime e, TimeSpan i, HistoryAggregateType a, CancellationToken ct) =>
+            NullHistorianDataSource.Instance.ReadProcessedAsync(r, s, e, i, a, ct);
+        public Task<CoreHistoryReadResult> ReadAtTimeAsync(string r, IReadOnlyList<DateTime> t, CancellationToken ct) =>
+            NullHistorianDataSource.Instance.ReadAtTimeAsync(r, t, ct);
+        public HistorianHealthSnapshot GetHealthSnapshot() => NullHistorianDataSource.Instance.GetHealthSnapshot();
+        public void Dispose() { }
+    }
+    /// <summary>Task-owned TCP relay. Pause blocks forwarding in both directions without closing either socket.</summary>
+    private sealed class PauseProxy : IAsyncDisposable
+    {
+        private readonly TcpListener _listener = new(IPAddress.Loopback, 0);
+        private readonly CancellationTokenSource _stop = new();
+        private readonly ConcurrentBag<TcpClient> _sockets = [];
+        private readonly ConcurrentBag<Task> _pumps = [];
+        private readonly Task _accept;
+        private TaskCompletionSource? _pause;
+        internal int Port => ((IPEndPoint)_listener.LocalEndpoint).Port;
+        internal PauseProxy(int targetPort)
+        {
+            _listener.Start();
+            _accept = AcceptAsync(targetPort);
+        }
+        internal void Pause() => Volatile.Write(ref _pause, new TaskCompletionSource(TaskCreationOptions.RunContinuationsAsynchronously));
+        internal void Resume() => Interlocked.Exchange(ref _pause, null)?.TrySetResult();
+        private async Task AcceptAsync(int port)
+        {
+            try
+            {
+                while (!_stop.IsCancellationRequested)
+                {
+                    var incoming = await _listener.AcceptTcpClientAsync(_stop.Token);
+                    _sockets.Add(incoming);
+                    var outgoing = new TcpClient(); _sockets.Add(outgoing);
+                    await outgoing.ConnectAsync(IPAddress.Loopback, port, _stop.Token);
+                    _pumps.Add(PumpAsync(incoming.GetStream(), outgoing.GetStream()));
+                    _pumps.Add(PumpAsync(outgoing.GetStream(), incoming.GetStream()));
+                }
+            }
+            catch (OperationCanceledException) when (_stop.IsCancellationRequested) { }
+        }
+        private async Task PumpAsync(NetworkStream source, NetworkStream destination)
+        {
+            var buffer = new byte[16 * 1024];
+            try
+            {
+                while (true)
+                {
+                    var length = await source.ReadAsync(buffer, _stop.Token);
+                    if (length == 0) return;
+                    if (Volatile.Read(ref _pause) is { } paused) await paused.Task.WaitAsync(_stop.Token);
+                    await destination.WriteAsync(buffer.AsMemory(0, length), _stop.Token);
+                }
+            }
+            catch (OperationCanceledException) when (_stop.IsCancellationRequested) { }
+            catch (IOException) when (_stop.IsCancellationRequested) { }
+        }
+        public async ValueTask DisposeAsync()
+        {
+            Resume(); _stop.Cancel(); _listener.Stop();
+            foreach (var socket in _sockets) socket.Dispose();
+            try { await _accept; await Task.WhenAll(_pumps); }
+            finally { _stop.Dispose(); }
+        }
+    }
+}
+
+internal sealed class OperationLedger
+{
+    private readonly ConcurrentDictionary<string,long> _counts=new();
+    internal void Record(string name)=>_counts.AddOrUpdate(name,1,(_,count)=>count+1);
+    internal async Task<T> Call<T>(string name,Func<Task<T>> operation)
+    {Record(name+".attempted");try{var value=await operation();Record(name+".returned");return value;}catch{Record(name+".faulted");throw;}}
+    internal async Task Call(string name,Func<Task> operation)
+    {Record(name+".attempted");try{await operation();Record(name+".returned");}catch{Record(name+".faulted");throw;}}
+    internal IReadOnlyDictionary<string,long> Snapshot()=>new SortedDictionary<string,long>(_counts);
+}
diff --git a/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/README.md b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/README.md
new file mode 100644
index 000000000..0860a4c98
--- /dev/null
+++ b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/README.md
@@ -0,0 +1,29 @@
+# SDK 1.5.378.182 comparator (lmxopcua#799)
+
+The owner's #799 scope asks for the matched SDK 1.5 comparator numbers next to the SDK2 acceptance runs. This
+comparator drives the canonical workload against the **immutable repaired SDK1 baseline `efb9197a`** (includes
+the #807 terminal-disposal fix), published RID-specific (`win-x64`, framework-dependent) from that commit and
+referenced, never rebuilt. It is `acceptance=false` by construction; it is evidence for comparison only.
+
+Sources: `BaselineRig.cs`, `BaselineMetrics.cs`, `CanonicalOperations.cs`, `Program.cs` are copies of
+`../baseline-canonical/` (the reviewed SDK1 port of the canonical operations, ported from the SDK2 soak at
+`75057d8c`), with exactly these changes:
+
+| Change | Why |
+|---|---|
+| `Program.cs`: the 1..4-cycle / 120 s short-smoke entry is replaced by `ComparatorAsync`, the late-slope loop: same cycle body, quiescent sample after every cycle, active restart every fourth cycle (25 s bound), 30 s cycle bound, 120 s startup bound, 7,200 s phase, cycle-3 cold baseline with the unchanged +64 MiB managed / +128 MiB RSS / +32 descriptor caps and a latched first rejection, then bounded shutdown checks. | The canonical late-slope protocol applied to SDK1. |
+| `CanonicalOperations.cs`: the held-reference zero closed-session continuation-list assertion is recorded per cycle (`closedSessionPointsWhileHeld`) instead of asserted; the 250 ms observation delay is removed. | SDK 1.5 `Session.Close` keeps the lists until `Dispose`; the baseline-canonical README/OWNERSHIP.md show this is not the SDK1 close contract and the objects are collected once harness roots drop. Asserting it would end the comparator at cycle 1. |
+| The 24-sample managed-monotonic guard is latched (recorded) rather than fatal. | So the comparator yields numbers for the full phase even if the old SDK grows; it is not a pass/fail gate. |
+| Steady inventories use SDK1 observables: `Server/ClientCachedStoreReferences` (validator cached store references) in place of SDK2 manager cached stores; no `ApplicationInstance.DisposeAsync` / manager-disposed checks. | Not present in SDK 1.5 (reported unsupported, never as zero). |
+| `WindowsDescriptors.cs`: byte-for-byte the SDK2 test's Windows descriptor observer. | Same descriptor/PKI semantics as the SDK2 Windows run. |
+| Samples also carry `PrivateBytes`. | Descriptive. |
+
+Known non-matched elements: the comparator is a standalone self-contained executable, while the SDK2 workload runs
+inside the VSTest testhost (xUnit v3), so absolute RSS includes different host overhead; compare growth relative to
+each run's own cycle-3 baseline. `OPCUA_CERTIFICATE_LEAK_TRACKING` has no SDK1 equivalent.
+
+```bash
+python3 build.py --host "$sdk1HostWinX64" --client "$sdk1ClientWinX64" --assertions "$dirWithShouldly" --output "$build"
+# on Windows:
+powershell -NoProfile -ExecutionPolicy Bypass -File launch.ps1 -Bin "$build\publish" -Output "$run" -SourceRevision "$rev"
+```
diff --git a/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/WindowsDescriptors.cs b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/WindowsDescriptors.cs
new file mode 100644
index 000000000..6515a668d
--- /dev/null
+++ b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/WindowsDescriptors.cs
@@ -0,0 +1,132 @@
+using System.ComponentModel;
+using System.Runtime.InteropServices;
+using System.Runtime.Versioning;
+using Microsoft.Win32.SafeHandles;
+
+/// <summary>Byte-for-byte the Windows descriptor observer of Sdk2LifecycleWindowsDescriptors.cs (lmxopcua#799), hosted for the SDK1 comparator.</summary>
+internal static class WindowsDescriptors
+{
+    [SupportedOSPlatform("windows")]
+    internal static Task<(int Total, int Pki)> CountAsync(CancellationToken ct, IReadOnlyList<string> roots)
+    {
+        var result = new TaskCompletionSource<(int Total, int Pki)>(TaskCreationOptions.RunContinuationsAsynchronously);
+        var thread = new Thread(() =>
+        {
+            try { result.TrySetResult(WindowsHandleCounts(roots)); }
+            catch (Exception error) { result.TrySetException(error); }
+        }) { IsBackground = true, Name = "soak-descriptor-probe" };
+        thread.Start();
+        return BoundAsync();
+
+        async Task<(int Total, int Pki)> BoundAsync()
+        {
+            try { return await result.Task.WaitAsync(TimeSpan.FromSeconds(5), ct).ConfigureAwait(false); }
+            catch (TimeoutException) { throw new TimeoutException("Descriptor probe exceeded its handle-enumeration deadline."); }
+        }
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static (int Total, int Pki) WindowsHandleCounts(IReadOnlyList<string> roots)
+    {
+        // Canonicalise the roots first and close those directory handles before the snapshot, so they are not counted.
+        var canonicalRoots = roots.Select(WindowsCanonicalRoot).Distinct(StringComparer.OrdinalIgnoreCase).ToArray();
+        var self = (nuint)Environment.ProcessId;
+        var length = 1 << 20;
+        while (true)
+        {
+            var buffer = Marshal.AllocHGlobal(length);
+            try
+            {
+                var status = NtQuerySystemInformation(SystemExtendedHandleInformation, buffer, length, out var needed);
+                if (status == StatusInfoLengthMismatch)
+                {
+                    length = Math.Max(length * 2, needed + (1 << 16));
+                    continue;
+                }
+                if (status != 0) throw new Win32Exception(RtlNtStatusToDosError(status), $"NtQuerySystemInformation failed (0x{status:X8}).");
+                var count = (long)Marshal.ReadIntPtr(buffer);
+                var entries = buffer + 2 * IntPtr.Size;
+                var entrySize = Marshal.SizeOf<HandleEntry>();
+                int total = 0, pki = 0;
+                var path = new char[32768];
+                for (long i = 0; i < count; i++)
+                {
+                    var entry = Marshal.PtrToStructure<HandleEntry>(entries + (nint)(i * entrySize));
+                    if (entry.UniqueProcessId != self) continue;
+                    total++;
+                    var handle = (nint)entry.HandleValue;
+                    // GetFileType is answered by the I/O manager without the file-object lock; only disk files and
+                    // directories go on to the name query (pipes, sockets and consoles cannot hold PKI material).
+                    if (GetFileType(handle) != FileTypeDisk) continue;
+                    var name = FinalPath(handle, path);
+                    if (name is not null && WithinWindowsRoots(name, canonicalRoots)) pki++;
+                }
+                return (total, pki);
+            }
+            finally { Marshal.FreeHGlobal(buffer); }
+        }
+    }
+
+    [SupportedOSPlatform("windows")]
+    private static string WindowsCanonicalRoot(string root)
+    {
+        var full = Path.TrimEndingDirectorySeparator(Path.GetFullPath(root));
+        if (!Directory.Exists(full)) return BaselineMetrics.CanonicalPath(full);
+        using var directory = CreateFileW(full, 0, FileShareAll, 0, OpenExisting, FileFlagBackupSemantics, 0);
+        if (directory.IsInvalid) throw new Win32Exception(Marshal.GetLastWin32Error(), "Cannot open a PKI root for canonicalisation.");
+        return FinalPath(directory.DangerousGetHandle(), new char[32768])
+            ?? throw new IOException("A PKI root has no final path.");
+    }
+
+    private static string? FinalPath(nint handle, char[] buffer)
+    {
+        var written = GetFinalPathNameByHandleW(handle, buffer, buffer.Length, 0);
+        if (written == 0 || written >= buffer.Length) return null; // Closed/reused between snapshot and query, or not a named file.
+        var name = new string(buffer, 0, (int)written);
+        if (name.StartsWith(@"\\?\UNC\", StringComparison.Ordinal)) return @"\\" + name[8..];
+        return name.StartsWith(@"\\?\", StringComparison.Ordinal) ? name[4..] : name;
+    }
+
+    private static bool WithinWindowsRoots(string path, IReadOnlyList<string> roots)
+    {
+        path = Path.TrimEndingDirectorySeparator(path);
+        return roots.Any(root => path.Equals(root, StringComparison.OrdinalIgnoreCase)
+            || path.StartsWith(root + Path.DirectorySeparatorChar, StringComparison.OrdinalIgnoreCase));
+    }
+
+    private const int SystemExtendedHandleInformation = 64;
+    private const int StatusInfoLengthMismatch = unchecked((int)0xC0000004);
+    private const uint FileTypeDisk = 1;
+    private const uint FileShareAll = 7;
+    private const uint OpenExisting = 3;
+    private const uint FileFlagBackupSemantics = 0x02000000;
+
+    [StructLayout(LayoutKind.Sequential)]
+    private struct HandleEntry
+    {
+        public nint Object;
+        public nuint UniqueProcessId;
+        public nuint HandleValue;
+        public uint GrantedAccess;
+        public ushort CreatorBackTraceIndex;
+        public ushort ObjectTypeIndex;
+        public uint HandleAttributes;
+        public uint Reserved;
+    }
+
+    [DllImport("ntdll.dll")]
+    private static extern int NtQuerySystemInformation(int informationClass, nint information, int length, out int returnLength);
+
+    [DllImport("ntdll.dll")]
+    private static extern int RtlNtStatusToDosError(int status);
+
+    [DllImport("kernel32.dll", SetLastError = true)]
+    private static extern uint GetFileType(nint handle);
+
+    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
+    private static extern uint GetFinalPathNameByHandleW(nint handle, [Out] char[] path, int length, uint flags);
+
+    [DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
+    private static extern SafeFileHandle CreateFileW(string name, uint access, uint share, nint security, uint disposition,
+        uint flags, nint template);
+}
diff --git a/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/build.py b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/build.py
new file mode 100644
index 000000000..444f68d0c
--- /dev/null
+++ b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/build.py
@@ -0,0 +1,80 @@
+#!/usr/bin/env python3
+"""Publish the SDK 1.5.378.182 comparator (lmxopcua#799) self-contained against an immutable SDK1 publication.
+
+Like ../baseline-canonical/build.py: never rebuilds product code. References come from the given RID-specific
+framework-dependent publications of the SDK1 host and client (host wins duplicate names; native DLLs are skipped as
+references and copied beside the output), plus Shouldly and its assertion dependencies. The comparator is published
+self-contained for the requested RID on the same pinned runtime as the SDK2 run (10.0.14).
+"""
+import argparse
+import hashlib
+import json
+from pathlib import Path
+import shutil
+import subprocess
+import xml.etree.ElementTree as ET
+
+RUNTIME = "10.0.14"
+SOURCES = ["Program.cs", "BaselineRig.cs", "BaselineMetrics.cs", "CanonicalOperations.cs", "WindowsDescriptors.cs"]
+
+
+def managed(path):
+    data = path.read_bytes()
+    if data[:2] != b"MZ":
+        return False
+    pe = int.from_bytes(data[0x3C:0x40], "little")
+    magic = int.from_bytes(data[pe + 24:pe + 26], "little")
+    directories = pe + 24 + (112 if magic == 0x20B else 96)
+    clr = directories + 14 * 8
+    return int.from_bytes(data[clr:clr + 4], "little") != 0
+
+
+parser = argparse.ArgumentParser(description=__doc__)
+parser.add_argument("--host", type=Path, required=True)
+parser.add_argument("--client", type=Path, required=True)
+parser.add_argument("--assertions", type=Path, required=True)
+parser.add_argument("--rid", default="win-x64")
+parser.add_argument("--output", type=Path, required=True)
+args = parser.parse_args()
+root = args.output.resolve()
+root.mkdir(parents=True, exist_ok=False)
+source = Path(__file__).resolve().parent
+references, natives = {}, {}
+for directory in [args.host, args.client]:
+    for dll in sorted(directory.resolve(strict=True).glob("*.dll")):
+        (references if managed(dll) else natives).setdefault(dll.name, dll)
+for name in ["Shouldly.dll", "DiffEngine.dll", "EmptyFiles.dll", "EmptyFiles.Xml.dll"]:
+    path = args.assertions.resolve(strict=True) / name
+    if path.exists():
+        references.setdefault(name, path)
+project = ET.Element("Project", Sdk="Microsoft.NET.Sdk")
+properties = ET.SubElement(project, "PropertyGroup")
+for key, value in {"OutputType": "Exe", "TargetFramework": "net10.0", "Nullable": "enable", "ImplicitUsings": "enable",
+                   "TreatWarningsAsErrors": "true", "EnableDefaultCompileItems": "false", "AssemblyName": "sdk1-comparator",
+                   "RuntimeIdentifier": args.rid, "SelfContained": "true", "RuntimeFrameworkVersion": RUNTIME,
+                   "NoWarn": "CA1416"}.items():
+    ET.SubElement(properties, key).text = value
+items = ET.SubElement(project, "ItemGroup")
+ET.SubElement(items, "FrameworkReference", Include="Microsoft.AspNetCore.App")
+for name, path in references.items():
+    reference = ET.SubElement(items, "Reference", Include=path.stem)
+    ET.SubElement(reference, "HintPath").text = str(path)
+for name in SOURCES:
+    ET.SubElement(items, "Compile", Include=str(source / name))
+path = root / "comparator.csproj"
+ET.indent(project)
+ET.ElementTree(project).write(path, encoding="unicode")
+publish = root / "publish"
+with (root / "build.log").open("w") as log:
+    result = subprocess.run(["dotnet", "publish", str(path), "-c", "Release", "-o", str(publish), "-m:2", "--nologo"],
+                            stdout=log, stderr=subprocess.STDOUT)
+if result.returncode == 0:
+    for name, native in natives.items():
+        if not (publish / name).exists():
+            shutil.copy2(native, publish / name)
+manifest = {"diagnosticOnly": True, "productRebuilt": False, "rid": args.rid, "runtime": RUNTIME,
+            "references": {n: hashlib.sha256(p.read_bytes()).hexdigest() for n, p in references.items()},
+            "natives": {n: hashlib.sha256(p.read_bytes()).hexdigest() for n, p in natives.items()},
+            "sources": {n: hashlib.sha256((source / n).read_bytes()).hexdigest() for n in SOURCES}}
+(root / "provenance.json").write_text(json.dumps(manifest, indent=2) + "\n")
+raise SystemExit(result.returncode)
diff --git a/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/launch.ps1 b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/launch.ps1
new file mode 100644
index 000000000..791644d95
--- /dev/null
+++ b/scripts/validation/opcua-lifecycle-memory/sdk1-comparator/launch.ps1
@@ -0,0 +1,48 @@
+<#
+.SYNOPSIS
+  Runs the SDK 1.5.378.182 comparator (lmxopcua#799) for 7,200 s on Windows with the same envelope as ../windows/launch.ps1:
+  private task directory for TEMP and fixture PKI, ephemeral fixture credential, external 30 s sampler, 7,440 s outer deadline.
+#>
+param(
+    [Parameter(Mandatory)] [string] $Bin,
+    [Parameter(Mandatory)] [string] $Output,
+    [Parameter(Mandatory)] [string] $SourceRevision
+)
+$ErrorActionPreference = 'Stop'
+if (Test-Path $Output) { throw 'Use a fresh output directory' }
+New-Item -ItemType Directory -Path $Output | Out-Null
+$Output = (Resolve-Path $Output).Path
+New-Item -ItemType Directory -Path (Join-Path $Output 'tmp') | Out-Null
+& icacls $Output /inheritance:r /grant:r "$($env:USERNAME):(OI)(CI)F" '*S-1-5-18:(OI)(CI)F' | Out-Null
+$exe = Join-Path (Resolve-Path $Bin).Path 'sdk1-comparator.exe'
+$started = Get-Date
+$bytes = New-Object byte[] 3; [System.Security.Cryptography.RandomNumberGenerator]::Create().GetBytes($bytes)
+$env:OTOPCUA_BASELINE_CANONICAL_KEY = 'otua_k-server-events_' + (($bytes | ForEach-Object { $_.ToString('x2') }) -join '')
+$env:OTOPCUA_COMPARATOR_SOURCE = $SourceRevision
+$env:TEMP = Join-Path $Output 'tmp'; $env:TMP = $env:TEMP
+@{ kind = 'comparator-launch'; sourceRevision = $SourceRevision; exe = $exe
+   exeSha256 = (Get-FileHash -Algorithm SHA256 $exe).Hash.ToLowerInvariant()
+   coreClrSha256 = (Get-FileHash -Algorithm SHA256 (Join-Path (Split-Path $exe) 'coreclr.dll')).Hash.ToLowerInvariant()
+   startedUtc = $started.ToUniversalTime().ToString('o'); credentialBytes = $env:OTOPCUA_BASELINE_CANONICAL_KEY.Length } |
+    ConvertTo-Json | Set-Content -Encoding UTF8 (Join-Path $Output 'launch.json')
+$psi = New-Object System.Diagnostics.ProcessStartInfo $exe
+$psi.Arguments = "`"$(Join-Path $Output 'run')`" 7200 --comparator"
+$psi.UseShellExecute = $false; $psi.RedirectStandardOutput = $true; $psi.RedirectStandardError = $true
+$proc = [System.Diagnostics.Process]::Start($psi)
+$outTask = $proc.StandardOutput.ReadToEndAsync(); $errTask = $proc.StandardError.ReadToEndAsync()
+$sampler = Join-Path $Output 'external-samples.jsonl'
+while (-not $proc.WaitForExit(30000)) {
+    $elapsed = ((Get-Date) - $started).TotalSeconds
+    $row = [ordered]@{ utc = (Get-Date).ToUniversalTime().ToString('o'); launcherElapsedSeconds = [math]::Round($elapsed, 1) }
+    try {
+        $p = Get-Process -Id $proc.Id -ErrorAction Stop
+        $row.workingSet64 = $p.WorkingSet64; $row.privateMemorySize64 = $p.PrivateMemorySize64
+        $row.peakWorkingSet64 = $p.PeakWorkingSet64; $row.handleCount = $p.HandleCount; $row.threads = $p.Threads.Count
+    } catch { $row.targetGone = $true }
+    ($row | ConvertTo-Json -Compress) | Add-Content -Encoding UTF8 $sampler
+    if ($elapsed -gt 7440) { & taskkill /PID $proc.Id /T /F | Out-Null; 'outer-deadline' | Set-Content (Join-Path $Output 'launcher-outcome.txt') }
+}
+Set-Content -Encoding UTF8 (Join-Path $Output 'stdout.log') $outTask.Result
+Set-Content -Encoding UTF8 (Join-Path $Output 'stderr.log') $errTask.Result
+"$($proc.ExitCode)" | Set-Content -Encoding ASCII (Join-Path $Output 'exit-status.txt')
+'done' | Add-Content (Join-Path $Output 'launcher-outcome.txt')