diff --git a/docs/drivers/MTConnect.md b/docs/drivers/MTConnect.md
index a2d62af9..3768a4c1 100644
--- a/docs/drivers/MTConnect.md
+++ b/docs/drivers/MTConnect.md
@@ -397,8 +397,21 @@ for anything beyond values-and-conditions.
    `DeviceName` (see [Write-back](#write-back--observation-injection-off-by-default)).
    So `MTConnectDriverOptions.DeviceName` does double duty — request scope for
    reads/browse, fallback write target for writes.
-3. **Nothing validates a raw tag's declared OPC UA `DataType` against the
-   blob's coercion type.** The `/probe`-sourced inference
+
+   **It is no longer silent (#613).** When the instance's raw tags carry two or
+   more distinct non-blank `RawTagEntry.DeviceName` values, driver init logs one
+   Warning naming them and the driver-level scope they collapse into. A single
+   value is not reported (it is just the `/raw` Device's own name). Real
+   per-device routing remains deferred.
+3. **Authoring only *warns* when a declared coercion type cannot hold the
+   inferred one (#613).** The AdminUI tag editor (`MTConnectTagConfigModel.Warnings()`)
+   compares the declared type with `MTConnectDataTypeInference` over the
+   `/probe` metadata a browse-commit stamped (`mtCategory`/`mtType`), and shows an
+   advisory line — it never blocks a save (the deploy gate does not refuse it) and
+   is a no-op for hand-authored blobs with no stamped metadata. `representation`
+   is not on the model, so TIME_SERIES arrays are not covered. Beyond that,
+   nothing validates a raw tag's declared OPC UA `DataType` against the
+   blob's coercion type. The `/probe`-sourced inference
    (`MTConnectDataTypeInference`) narrows how often an author picks a wrong
    type, but it doesn't close the gap — an authored `DataType` mismatched
    against the actual Agent observation still surfaces as `BadTypeMismatch`
diff --git a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect/MTConnectDriver.cs b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect/MTConnectDriver.cs
index 95f76c3e..5001c1aa 100644
--- a/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect/MTConnectDriver.cs
+++ b/src/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect/MTConnectDriver.cs
@@ -3232,6 +3232,29 @@ public sealed class MTConnectDriver
 
     // ---- v3 tag binding: RawPath ↔ dataItemId, and the definitions the index coerces against ----
 
+    /// <summary>
+    ///     Names the distinct, non-blank <see cref="RawTagEntry.DeviceName"/> values when there are two or
+    ///     more, else <c>null</c> (#613). The driver never routes by that field — one instance owns one
+    ///     Agent client — so differing values mean the author expects a split the driver silently does
+    ///     not perform. A single value is NOT reported: it is the <c>/raw</c> Device's own name, which
+    ///     routinely differs from the Agent's device name and would make the warning noise.
+    /// </summary>
+    /// <param name="rawTags">The authored raw tags.</param>
+    /// <returns>A comma-joined, sorted list of the distinct names, or <c>null</c> when fewer than two.</returns>
+    internal static string? DescribeIgnoredDeviceNames(IReadOnlyList<RawTagEntry> rawTags)
+    {
+        var names = new SortedSet<string>(StringComparer.Ordinal);
+        foreach (var entry in rawTags)
+        {
+            if (entry is not null && !string.IsNullOrWhiteSpace(entry.DeviceName))
+            {
+                names.Add(entry.DeviceName.Trim());
+            }
+        }
+
+        return names.Count >= 2 ? string.Join(", ", names) : null;
+    }
+
     /// <summary>
     ///     Derives the driver's tag tables from an options document — the <c>RawPath → dataItemId</c>
     ///     translation the data plane runs through, its reverse, and the definition set the
@@ -3295,6 +3318,13 @@ public sealed class MTConnectDriver
                 BuildWriteTargets(only, probeModel, options.DeviceName));
         }
 
+        if (DescribeIgnoredDeviceNames(options.RawTags) is { } ignoredDevices)
+        {
+            _logger.LogWarning(
+                "MTConnect driver {DriverInstanceId}: raw tags carry differing DeviceName values ({DeviceNames}), but RawTagEntry.DeviceName is not used for routing — every tag is served from the one Agent connection scoped by the driver-level DeviceName ({ConfiguredDevice}). Author one MTConnect driver instance per Agent device if they must be kept apart.",
+                _driverInstanceId, ignoredDevices, options.DeviceName ?? "<whole Agent>");
+        }
+
         var declared = IndexProbeDataItems(probeModel);
         var idByRawPath = new Dictionary<string, string>(options.RawTags.Count, StringComparer.Ordinal);
         var rawPathsById = new Dictionary<string, List<string>>(StringComparer.Ordinal);
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/MTConnectTagConfigEditor.razor b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/MTConnectTagConfigEditor.razor
index 7a71f951..2db13693 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/MTConnectTagConfigEditor.razor
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Components/Shared/Uns/TagEditors/MTConnectTagConfigEditor.razor
@@ -80,6 +80,10 @@
 {
     <div class="text-danger small mt-2">@error</div>
 }
+@foreach (var warning in _m.Warnings())
+{
+    <div class="text-warning small mt-2">@warning</div>
+}
 
 @code {
     /// <summary>The tag's raw TagConfig JSON (supports <c>@bind-ConfigJson</c>).</summary>
diff --git a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/MTConnectTagConfigModel.cs b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/MTConnectTagConfigModel.cs
index b68a4429..d1d3997a 100644
--- a/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/MTConnectTagConfigModel.cs
+++ b/src/Server/ZB.MOM.WW.OtOpcUa.AdminUI/Uns/TagEditors/MTConnectTagConfigModel.cs
@@ -216,6 +216,55 @@ public sealed class MTConnectTagConfigModel
             "MTConnect");
     }
 
+    /// <summary>
+    ///     Advisory warnings (#613) — NEVER an error and never routed through <see cref="Validate"/>: the
+    ///     deploy gate does not refuse these, so authoring must not either ("never stricter than the gate").
+    ///     One rule: the declared <see cref="DataType"/> cannot hold the type
+    ///     <see cref="MTConnectDataTypeInference.Infer"/> derives from the stamped
+    ///     <see cref="MtCategory"/>/<see cref="MtType"/>.
+    /// </summary>
+    /// <remarks>
+    ///     A no-op unless the probe metadata was stamped (a browse-commit does; hand-authored blobs do not),
+    ///     since there is nothing to infer from otherwise. <c>representation</c> is not on the model so it is
+    ///     passed as null; it can only DEMOTE an item to String (DATA_SET/TABLE), which cannot create a false
+    ///     warning because a numeric declaration on a String-inferred item is warned either way, and a SAMPLE
+    ///     inferred Float64 is only warned about for a non-numeric, non-String declaration or an integer one.
+    ///     TIME_SERIES arrays are not detectable without it and are not covered.
+    /// </remarks>
+    /// <returns>Zero or more human-readable warnings.</returns>
+    public IReadOnlyList<string> Warnings()
+    {
+        if (string.IsNullOrWhiteSpace(MtCategory)) { return []; }
+
+        var inferred = MTConnectDataTypeInference.Infer(MtCategory, MtType, Units).DataType;
+        var declared = DataType;
+
+        // String can hold any observation's text, so declaring it is never lossy.
+        if (declared == inferred || declared == DriverDataType.String) { return []; }
+
+        if (IsNumeric(inferred) && IsNumeric(declared))
+        {
+            // Float64 inferred (a SAMPLE): an integer type cannot hold a fractional reading. A wider-or-equal
+            // numeric holds an Int64-inferred item (PartCount, Line).
+            return IsIntegral(declared) && !IsIntegral(inferred)
+                ? [$"Data type {declared} cannot hold fractional values; the Agent's /probe metadata "
+                    + $"({MtCategory}/{MtType}) infers {inferred}. Fractional readings will surface as a bad status."]
+                : [];
+        }
+
+        return
+        [
+            $"Data type {declared} does not match the type inferred from the Agent's /probe metadata "
+            + $"({MtCategory}/{MtType} -> {inferred}). Observations that do not parse as {declared} will surface "
+            + "as BadTypeMismatch/BadOutOfRange at runtime. Saving is still allowed."
+        ];
+    }
+
+    private static bool IsNumeric(DriverDataType t) => t is not (DriverDataType.Boolean or DriverDataType.String
+        or DriverDataType.DateTime or DriverDataType.Reference);
+
+    private static bool IsIntegral(DriverDataType t) => IsNumeric(t) && t is not (DriverDataType.Float32 or DriverDataType.Float64);
+
     // The as-loaded coercion-type TOKEN as text (see the _rawDataType and DataTypeKeys remarks), read in
     // the RUNTIME's precedence so this model judges — and displays — the token the driver would actually
     // read. Per key, mirroring FirstNonBlank(blob.DriverDataType, blob.DataType) over a DTO whose two
diff --git a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect.Tests/MTConnectRawTagBindingTests.cs b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect.Tests/MTConnectRawTagBindingTests.cs
index 9f12645e..d022c070 100644
--- a/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect.Tests/MTConnectRawTagBindingTests.cs
+++ b/tests/Drivers/ZB.MOM.WW.OtOpcUa.Driver.MTConnect.Tests/MTConnectRawTagBindingTests.cs
@@ -117,6 +117,37 @@ public sealed class MTConnectRawTagBindingTests
         return (driver, agent);
     }
 
+    private static RawTagEntry OnDevice(string rawPath, string dataItemId, string device) =>
+        Entry(rawPath, dataItemId) with { DeviceName = device };
+
+    private static async Task<List<string>> InitWarningsAsync(params RawTagEntry[] rawTags)
+    {
+        var logger = new RecordingDriverLogger();
+        var driver = new MTConnectDriver(Bare(), "mt1", _ => CannedAgentClient.FromFixtures(), logger);
+        await driver.InitializeAsync(MergedConfig(rawTags), Ct);
+        await driver.ShutdownAsync(Ct);
+
+        return [.. logger.Warnings];
+    }
+
+    /// <summary>#613: differing RawTagEntry.DeviceName values are ignored for routing, so init says so.</summary>
+    [Fact]
+    public async Task Differing_raw_device_names_log_an_ignored_routing_warning()
+    {
+        // Positive control: a single /raw Device is the ordinary case and must stay silent.
+        (await InitWarningsAsync(
+            OnDevice(PositionRawPath, PositionDataItemId, "cncA"),
+            OnDevice(ExecutionRawPath, ExecutionDataItemId, "cncA")))
+            .ShouldNotContain(w => w.Contains("RawTagEntry.DeviceName"));
+
+        var warnings = await InitWarningsAsync(
+            OnDevice(PositionRawPath, PositionDataItemId, "cncA"),
+            OnDevice(ExecutionRawPath, ExecutionDataItemId, "cncB"));
+
+        var w = warnings.Where(x => x.Contains("RawTagEntry.DeviceName")).ShouldHaveSingleItem();
+        w.ShouldContain("cncA, cncB");
+    }
+
     // ---- the production data plane: subscribe by RawPath, publish by RawPath ----
 
     /// <summary>
diff --git a/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/MTConnectTagConfigModelTests.cs b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/MTConnectTagConfigModelTests.cs
index 8374ebe5..a40e62d7 100644
--- a/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/MTConnectTagConfigModelTests.cs
+++ b/tests/Server/ZB.MOM.WW.OtOpcUa.AdminUI.Tests/Uns/MTConnectTagConfigModelTests.cs
@@ -295,4 +295,37 @@ public sealed class MTConnectTagConfigModelTests
     [InlineData("""{"fullName":"x","driverDataType":8,"dataType":"Int32"}""")]
     public void Validate_rejects_a_driverDataType_written_as_an_unquoted_number(string json)
         => MTConnectTagConfigModel.FromJson(json).Validate().ShouldNotBeNull().ShouldContain("8");
+
+    private static MTConnectTagConfigModel Stamped(string category, string type, string dataType)
+        => MTConnectTagConfigModel.FromJson(
+            $"{{\"fullName\":\"x\",\"dataType\":\"{dataType}\",\"mtCategory\":\"{category}\",\"mtType\":\"{type}\"}}");
+
+    [Theory]
+    [InlineData("SAMPLE", "POSITION", "Boolean")]   // numeric inferred, non-numeric declared
+    [InlineData("SAMPLE", "POSITION", "Int32")]     // fractional readings cannot fit
+    [InlineData("EVENT", "EXECUTION", "Float64")]   // text inferred, numeric declared
+    [InlineData("CONDITION", "TEMPERATURE", "Int32")]
+    public void Warnings_flags_a_declared_type_that_cannot_hold_the_inferred_one_without_blocking(
+        string category, string type, string dataType)
+    {
+        var m = Stamped(category, type, dataType);
+
+        m.Warnings().ShouldHaveSingleItem().ShouldContain(dataType);
+        m.Validate().ShouldBeNull(); // advisory: never blocks
+    }
+
+    [Theory]
+    [InlineData("SAMPLE", "POSITION", "Float64")]
+    [InlineData("SAMPLE", "POSITION", "String")]    // text holds anything
+    [InlineData("EVENT", "EXECUTION", "String")]
+    [InlineData("EVENT", "PART_COUNT", "Int64")]
+    [InlineData("EVENT", "PART_COUNT", "Float64")]
+    public void Warnings_is_quiet_when_the_declared_type_holds_the_inferred_one(
+        string category, string type, string dataType)
+        => Stamped(category, type, dataType).Warnings().ShouldBeEmpty();
+
+    [Fact]
+    public void Warnings_is_a_noop_without_probe_metadata()
+        => MTConnectTagConfigModel.FromJson("{\"fullName\":\"x\",\"dataType\":\"Boolean\"}")
+            .Warnings().ShouldBeEmpty();
 }