diff --git a/tests/ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests/Design/TemplateCrudTests.cs b/tests/ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests/Design/TemplateCrudTests.cs
index 5b16db54..9daf8689 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests/Design/TemplateCrudTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests/Design/TemplateCrudTests.cs
@@ -1,5 +1,7 @@
 using Microsoft.Playwright;
 using ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests.Cluster;
+using ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests.Deployment;
+using Xunit;
 
 namespace ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests.Design;
 
@@ -9,13 +11,15 @@ namespace ZB.MOM.WW.ScadaBridge.CentralUI.PlaywrightTests.Design;
 /// running dev cluster.
 /// </summary>
 [Collection("Playwright")]
-public class TemplateCrudTests
+public class TemplateCrudTests : IClassFixture<DeploymentFixture>
 {
     private readonly PlaywrightFixture _fixture;
+    private readonly DeploymentFixture _cluster;
 
-    public TemplateCrudTests(PlaywrightFixture fixture)
+    public TemplateCrudTests(PlaywrightFixture fixture, DeploymentFixture cluster)
     {
         _fixture = fixture;
+        _cluster = cluster;
     }
 
     [SkippableFact]
@@ -212,4 +216,122 @@ public class TemplateCrudTests
             }
         }
     }
+
+    [SkippableFact]
+    public async Task EditAttribute_PersistsChange()
+    {
+        Skip.IfNot(await ClusterAvailability.IsAvailableAsync(), ClusterAvailability.SkipReason);
+
+        // CLI-seed a template with a single Double "Val" attribute, then edit its
+        // Value through the page-local Edit-Attribute modal and confirm it persists.
+        var name = CliRunner.UniqueName("tmpl");
+        var id = await CliRunner.CreateTemplateAsync(name);
+        await CliRunner.AddAttributeAsync(id, "Val", "Double");
+
+        try
+        {
+            var page = await _fixture.NewAuthenticatedPageAsync();
+
+            await page.GotoAsync($"{PlaywrightFixture.BaseUrl}/design/templates/{id}");
+            await page.WaitForLoadStateAsync(LoadState.NetworkIdle);
+
+            // Open the Val row's actions dropdown, then click the "Edit…" item
+            // (note the ellipsis char "…" — it is in the markup verbatim).
+            await page.ClickAsync("button[aria-label=\"More actions for Val\"]");
+            await page.ClickAsync("button.dropdown-item:has-text('Edit…')");
+
+            // The page-local attribute modal is .modal.show.d-block WITHOUT `fade`
+            // (the DialogHost confirm modal HAS `fade`). :not(.fade) pins the
+            // page-local one.
+            var modal = page.Locator(".modal.show.d-block:not(.fade)");
+            await Assertions.Expect(modal).ToBeVisibleAsync();
+            await Assertions.Expect(modal.Locator("h6.modal-title")).ToHaveTextAsync("Edit Attribute");
+
+            // When editing, the Name input is rendered readonly (readonly="@editing").
+            await Assertions.Expect(
+                modal.Locator("div.col-12:has(label:has-text('Name')) input.form-control"))
+                .ToHaveAttributeAsync("readonly", "");
+
+            // The Value input is label-anchored: its containing div carries the
+            // "Value" label. ("Data Source Ref" does not contain "Value", so the
+            // substring match resolves uniquely to the Value field.)
+            var valueInput = modal.Locator("div.col-12:has(label:has-text('Value')) input.form-control");
+            await valueInput.FillAsync("42.5");
+
+            // Footer button text is "Save" when editing (vs "Add" when adding).
+            await modal.Locator(".modal-footer button.btn-success.btn-sm:has-text('Save')").ClickAsync();
+
+            // SaveAttribute persists then reloads, dismissing the modal.
+            await Assertions.Expect(modal).ToHaveCountAsync(0, new() { Timeout = 10_000 });
+
+            // The attribute table renders the value in a <td class="small">@effectiveValue</td>
+            // cell (for a non-derived template effectiveValue == attr.Value), so the
+            // persisted "42.5" must appear in the Val row's value cell. Web-first wait
+            // covers the post-save reload.
+            await Assertions.Expect(page.Locator("table td.small:has-text('42.5')"))
+                .ToBeVisibleAsync(new() { Timeout = 10_000 });
+        }
+        finally
+        {
+            await CliRunner.DeleteTemplateAsync(id);
+            // Defensive sweep by name in case the delete above was a no-op.
+            try
+            {
+                foreach (var leftover in await CliRunner.ListTemplateIdsByNamePrefixAsync(name))
+                {
+                    await CliRunner.DeleteTemplateAsync(leftover);
+                }
+            }
+            catch
+            {
+                // Best-effort — swallow to avoid masking the original test failure.
+            }
+        }
+    }
+
+    [SkippableFact]
+    public async Task DeleteTemplate_WithInstance_IsBlocked()
+    {
+        Skip.IfNot(_cluster.Available, ClusterAvailability.SkipReason);
+
+        // Mint a non-deployed instance referencing the fixture's template — that
+        // reference is sufficient for TemplateDeletionService to block the delete
+        // with the "instance(s) reference it" error.
+        var (instId, _) = await _cluster.CreateInstanceAsync();
+        try
+        {
+            var page = await _fixture.NewAuthenticatedPageAsync();
+
+            await page.GotoAsync($"{PlaywrightFixture.BaseUrl}/design/templates/{_cluster.TemplateId}");
+            await page.WaitForLoadStateAsync(LoadState.NetworkIdle);
+
+            // Header Delete button (btn-outline-danger btn-sm).
+            await page.ClickAsync("button.btn.btn-outline-danger.btn-sm:has-text('Delete')");
+
+            // Confirm via the global DialogHost modal's danger button (labelled
+            // "Delete"). This modal HAS the `fade` class — distinct from the
+            // page-local attribute modal.
+            var confirmBtn = page.Locator(".modal-footer .btn-danger:has-text('Delete')");
+            await Assertions.Expect(confirmBtn).ToBeVisibleAsync(new() { Timeout = 5_000 });
+            await confirmBtn.ClickAsync();
+
+            // The delete fails: DeleteTemplate surfaces result.Error on a toast and
+            // does NOT navigate. The error reads
+            // "Cannot delete template '{name}': {n} instance(s) reference it (...)".
+            await Assertions.Expect(page.Locator(".toast"))
+                .ToContainTextAsync("instance(s) reference it", new() { Timeout = 10_000 });
+
+            // The template still exists — the page stayed on the detail URL because
+            // the failed delete did not navigate away.
+            await Assertions.Expect(page)
+                .ToHaveURLAsync(new System.Text.RegularExpressions.Regex(
+                    $"/design/templates/{_cluster.TemplateId}$"));
+        }
+        finally
+        {
+            // Remove this test's instance so the fixture template is instance-free
+            // again; the fixture's DisposeAsync sweeps the template + any leftovers.
+            await CliRunner.DeleteInstanceAsync(instId);
+        }
+    }
 }