diff --git a/crates/oa-desktop/src/app.rs b/crates/oa-desktop/src/app.rs
index a94df1df..a7ca8cf4 100644
--- a/crates/oa-desktop/src/app.rs
+++ b/crates/oa-desktop/src/app.rs
@@ -2766,7 +2766,15 @@ impl App {
                 }
                 self.reconcile_multiselect();
                 self.selected_bend = menu.request.bend.map(|i| (menu.request.object, i));
-                return self.update(*action);
+                let action = match *action {
+                    Message::EditProperties(id)
+                        if menu.request.canvas.is_some() && id == menu.request.object =>
+                    {
+                        Message::InspectorTab(crate::navigation::InspectorTab::Properties)
+                    }
+                    action => action,
+                };
+                return self.update(action);
             }
             Message::CreateContextElement(kind, child) => {
                 self.create_kind = kind;
@@ -3377,7 +3385,7 @@ impl App {
                     self.workflow = Some(crate::workflow::Workflow::relationship_kind(
                         self.project(),
                         self.selected,
-                        self.layer,
+                        self.project().layer_of(self.selected).unwrap_or(self.layer),
                         kind,
                         incoming,
                     ));
@@ -4403,13 +4411,18 @@ impl App {
             self.status = "Select an SA function or participant, then choose a typed port action in Properties.".into();
             return;
         }
+        let creation_layer = if child {
+            self.project().layer_of(self.selected).unwrap_or(self.layer)
+        } else {
+            self.layer
+        };
         let allocated = child
             && self.create_kind.is_work()
             && self
                 .project()
                 .elements
                 .get(&self.selected)
-                .is_some_and(|e| e.layer() == self.layer && e.kind().is_performer());
+                .is_some_and(|e| e.layer() == creation_layer && e.kind().is_performer());
         let parent = if child && !allocated {
             Some(self.selected)
         } else {
@@ -4417,7 +4430,7 @@ impl App {
         };
         let Some(e) = self.project().make_element(
             self.create_kind,
-            self.layer,
+            creation_layer,
             &format!("New {}", self.create_kind.label().to_lowercase()),
             parent,
         ) else {
@@ -4446,16 +4459,16 @@ impl App {
                 .project()
                 .diagrams
                 .values()
-                .find(|d| d.layer == self.layer && d.projection == preferred)
+                .find(|d| d.layer == creation_layer && d.projection == preferred)
                 .map(|d| d.id);
             if diagram_target.is_none() {
                 let view = Id::new_v4();
                 commands.push(Command::CreateDiagram(Diagram {
                     id: view,
                     alias: self.project().fresh_alias("engineering_view", "view", view),
-                    name: format!("{} {preferred}", self.layer),
+                    name: format!("{} {preferred}", creation_layer),
                     description: String::new(),
-                    layer: self.layer,
+                    layer: creation_layer,
                     projection: preferred,
                     layout: None,
                     routes: Vec::new(),
@@ -4588,7 +4601,13 @@ impl App {
             ));
         }
         if self.execute(Command::Batch(commands)) {
+            let changed_view = self.active_diagram != diagram_target;
             self.active_diagram = diagram_target;
+            if changed_view
+                && let Some(view) = diagram_target.and_then(|id| self.project().diagrams.get(&id))
+            {
+                self.layer = view.layer;
+            }
             self.selected = id;
             self.inspector_tab = crate::navigation::InspectorTab::Properties;
             self.refresh_draft();
@@ -4602,7 +4621,7 @@ impl App {
         self.workflow = Some(crate::workflow::Workflow::relationship(
             self.project(),
             self.selected,
-            self.layer,
+            self.project().layer_of(self.selected).unwrap_or(self.layer),
         ));
     }
     fn add_trace(&mut self) {
diff --git a/crates/oa-desktop/src/app/canvas_selection_tests.rs b/crates/oa-desktop/src/app/canvas_selection_tests.rs
index 63b1687c..6746f904 100644
--- a/crates/oa-desktop/src/app/canvas_selection_tests.rs
+++ b/crates/oa-desktop/src/app/canvas_selection_tests.rs
@@ -295,3 +295,251 @@ fn cross_layer_port_inspection_and_connection_start_retain_the_view() {
     assert_eq!(app.connection.as_ref().unwrap().source, Some(port));
     assert!(!app.document.can_undo());
 }
+
+fn authoring_fixture(performer: bool) -> (Fixture, Id) {
+    let mut f = fixture();
+    let mut project = f.app.project().clone();
+    let owner = project
+        .add_element(
+            if performer {
+                Kind::Entity
+            } else {
+                Kind::Activity
+            },
+            Layer::Oa,
+            "Operational owner",
+            None,
+        )
+        .unwrap();
+    let target = project
+        .add_element(Kind::Activity, Layer::Oa, "Operational target", None)
+        .unwrap();
+    let placement = project.place(f.diagram, owner, Position { x: 0., y: 400. });
+    project.place(f.diagram, target, Position { x: 500., y: 400. });
+    f.app = App::with_project(project);
+    f.app.page = Page::Diagram;
+    f.app.layer = Layer::Sa;
+    f.app.active_diagram = Some(f.diagram);
+    f.app.selected = f.diagram;
+    f.app.refresh_draft();
+    f.app.reconcile_multiselect();
+    f.process = owner;
+    f.placement = placement;
+    (f, target)
+}
+
+fn assert_source_pair(app: &App) {
+    let compiled = oa_core::source_project::compile_bundle(
+        app.document.bundle(),
+        oa_core::source_project::ProjectLimits::default(),
+    )
+    .unwrap();
+    assert_eq!(&compiled.decoded.project, app.project());
+    assert_eq!(&compiled.bundle, app.document.bundle());
+}
+
+#[test]
+fn mixed_canvas_relationship_actions_keep_operational_source_and_commit_one_step() {
+    for context_action in [false, true] {
+        let (mut f, target) = authoring_fixture(false);
+        let before = f.app.document.snapshot();
+        let owner = f.process;
+        let placement = f.placement;
+        if context_action {
+            invoke(
+                &mut f,
+                owner,
+                Some(placement),
+                Message::AddRelationKind(RelationKind::Interaction, false),
+            );
+        } else {
+            let _ = f.app.update(Message::SelectNode(placement));
+            let _ = f.app.update(Message::AddRelation);
+        }
+        assert_surface(&f);
+        let Some(crate::workflow::Workflow::Relation(relation)) = &f.app.workflow else {
+            panic!("relationship form did not open: {}", f.app.status);
+        };
+        assert_eq!(
+            relation.source.as_ref().map(|source| source.id),
+            Some(owner)
+        );
+        assert_eq!(relation.kind, RelationKind::Interaction);
+        let saved = f
+            .app
+            .workflow
+            .as_ref()
+            .unwrap()
+            .recovery_snapshot()
+            .unwrap();
+        assert_eq!(saved["Relation"]["layer"], "Oa");
+        let _ = f
+            .app
+            .update(Message::Workflow(crate::workflow::Event::Target(Choice {
+                id: target,
+                label: "Operational target".into(),
+            })));
+        let _ = f
+            .app
+            .update(Message::Workflow(crate::workflow::Event::Apply));
+        assert!(f.app.workflow.is_none(), "{}", f.app.status);
+        let created: Vec<_> = f
+            .app
+            .project()
+            .relations
+            .values()
+            .filter(|relation| !before.decoded.project.relations.contains_key(&relation.id))
+            .collect();
+        assert_eq!(created.len(), 1);
+        assert_eq!(
+            (created[0].kind(), created[0].source(), created[0].target()),
+            (RelationKind::Interaction, owner, target)
+        );
+        assert_source_pair(&f.app);
+        let _ = f.app.update(Message::Undo);
+        assert_eq!(f.app.project(), &before.decoded.project);
+        assert_eq!(f.app.document.bundle(), &before.bundle);
+        assert!(!f.app.document.can_undo());
+    }
+}
+
+#[test]
+fn mixed_canvas_add_child_command_uses_parent_layer_for_containment_and_allocation() {
+    for performer in [false, true] {
+        let (mut f, _) = authoring_fixture(performer);
+        let before = f.app.document.snapshot();
+        let owner = f.process;
+        let placement = f.placement;
+        invoke(
+            &mut f,
+            owner,
+            Some(placement),
+            Message::CreateContextElement(Kind::Activity, true),
+        );
+        assert_surface(&f);
+        let created: Vec<_> = f
+            .app
+            .project()
+            .elements
+            .values()
+            .filter(|element| !before.decoded.project.elements.contains_key(&element.id))
+            .collect();
+        assert_eq!(created.len(), 1, "{}", f.app.status);
+        let child = created[0].id;
+        assert_eq!(created[0].kind(), Kind::Activity);
+        assert_eq!(created[0].layer(), Layer::Oa);
+        assert_eq!(
+            created[0].parent,
+            if performer { None } else { Some(owner) }
+        );
+        let allocations: Vec<_> = f
+            .app
+            .project()
+            .relations
+            .values()
+            .filter(|relation| !before.decoded.project.relations.contains_key(&relation.id))
+            .collect();
+        assert_eq!(allocations.len(), usize::from(performer));
+        if performer {
+            assert_eq!(
+                (
+                    allocations[0].kind(),
+                    allocations[0].source(),
+                    allocations[0].target()
+                ),
+                (RelationKind::Allocation, owner, child)
+            );
+        }
+        assert!(
+            f.app.project().diagrams[&f.diagram]
+                .nodes
+                .values()
+                .any(|node| node.element == child)
+        );
+        assert_source_pair(&f.app);
+        let _ = f.app.update(Message::Undo);
+        assert_eq!(f.app.project(), &before.decoded.project);
+        assert_eq!(f.app.document.bundle(), &before.bundle);
+        assert!(!f.app.document.can_undo());
+    }
+}
+
+#[test]
+fn mixed_canvas_root_creation_still_uses_the_active_perspective() {
+    let (mut f, _) = authoring_fixture(false);
+    let _ = f.app.update(Message::SelectNode(f.placement));
+    let before = f.app.document.snapshot();
+    let _ = f
+        .app
+        .update(Message::CreateContextElement(Kind::Function, false));
+    assert_surface(&f);
+    let created: Vec<_> = f
+        .app
+        .project()
+        .elements
+        .values()
+        .filter(|element| !before.decoded.project.elements.contains_key(&element.id))
+        .collect();
+    assert_eq!(created.len(), 1, "{}", f.app.status);
+    assert_eq!(created[0].kind(), Kind::Function);
+    assert_eq!(created[0].layer(), Layer::Sa);
+    assert_eq!(created[0].parent, None);
+    assert_source_pair(&f.app);
+    let _ = f.app.update(Message::Undo);
+    assert_eq!(f.app.project(), &before.decoded.project);
+    assert_eq!(f.app.document.bundle(), &before.bundle);
+}
+
+#[test]
+fn child_creation_navigates_to_a_parent_layer_preferred_view_only_when_needed() {
+    for existing_preferred in [false, true] {
+        let (mut f, _) = authoring_fixture(false);
+        let mut project = f.app.project().clone();
+        for diagram in project
+            .diagrams
+            .values_mut()
+            .filter(|d| d.layer == Layer::Oa)
+        {
+            diagram.projection = if existing_preferred {
+                ProjectionKind::Allocation
+            } else {
+                ProjectionKind::Overview
+            };
+        }
+        f.app = App::with_project(project);
+        f.app.page = Page::Diagram;
+        f.app.layer = Layer::Sa;
+        f.app.active_diagram = Some(f.diagram);
+        f.app.selected = f.diagram;
+        f.app.refresh_draft();
+        let _ = f.app.update(Message::SelectNode(f.placement));
+        let _ = f
+            .app
+            .update(Message::Projection(ProjectionKind::Capabilities));
+        assert_eq!(f.app.selected, f.process);
+        let before = f.app.document.snapshot();
+        let _ = f
+            .app
+            .update(Message::CreateContextElement(Kind::Activity, true));
+        assert_eq!(f.app.layer, Layer::Oa, "{}", f.app.status);
+        let diagram = f.app.active_diagram.unwrap();
+        assert_ne!(diagram, f.diagram);
+        assert_eq!(f.app.project().diagrams[&diagram].layer, Layer::Oa);
+        assert_eq!(
+            f.app.project().diagrams[&diagram].projection,
+            ProjectionKind::Allocation
+        );
+        assert_eq!(
+            f.app.project().diagrams.len(),
+            before.decoded.project.diagrams.len() + usize::from(!existing_preferred)
+        );
+        assert_eq!(
+            f.app.project().elements[&f.app.selected].parent,
+            Some(f.process)
+        );
+        assert_source_pair(&f.app);
+        let _ = f.app.update(Message::Undo);
+        assert_eq!(f.app.project(), &before.decoded.project);
+        assert_eq!(f.app.document.bundle(), &before.bundle);
+    }
+}
diff --git a/harness/projection-navigation-20260925.md b/harness/projection-navigation-20260925.md
index db12c024..81b8cab3 100644
--- a/harness/projection-navigation-20260925.md
+++ b/harness/projection-navigation-20260925.md
@@ -29,8 +29,10 @@ Canvas inspection carries the originating route context and preserves view/layer
 Explicit model navigation continues to follow the target layer. Draft validation
 and stale-context rejection apply before inspection. Existing production group
 selection already retained the canvas; fallback edge/port selection and canvas
-context actions require the correction. Actual native reproduction must establish
-which path accounts for the user's reported click; source diagnosis alone does not.
+context actions require the correction. The published Windows baseline reproduces both reported failure states;
+source diagnosis and those baseline results do not establish patched acceptance.
+Contextual child/relationship creation must derive the semantic layer from the
+selected object, while root creation continues to use the active perspective.
 
 ## Acceptance
 
@@ -49,4 +51,12 @@ which path accounts for the user's reported click; source diagnosis alone does n
 
 Linux remains excluded by the existing user pause. Independent design critique
 identified saved visibility selectors and frozen migration as additional admission
-paths; both are included. Automated and native outcomes are not yet recorded.
+paths; both are included. At published candidate `603a59c1785dbcca324dae063ecc3405d9519a30`, 41 targeted core checks pass: legacy admission (2), projection switching (3), review regressions (15), source-6 view contract (8), and state diagrams (13). Tracked inputs were unchanged across the run. Whole-workspace formatting also passed at that commit. The first `0341bca` core attempt failed a generated-UUID test oracle; explicit fixture identities corrected the evaluator, without relaxing the admission assertion.
+
+The desktop attempt at `603a59c` was deliberately interrupted before test execution after independent source review found canvas Properties redispatch and contextual relationship/child semantic-layer defects. Its source inputs remained unchanged; no desktop passing result is claimed. The Properties issue arose from fixing explicit navigation to an already-inspected opposite-layer object. Keep both regressions: contextual Properties stays in the view, explicit navigation follows the object's layer.
+
+Published-preview executable SHA256 `2c03bd6cc3f1110c219e4f57ab94874a121590f83779239a93289b7170664399` reproduces edge selection changing SA to OA, and Architecture switching refused with `diagram_layer`. The isolated valid fixture remained byte-for-byte unchanged after the trial. An earlier fixture used reserved alias `capability` and was rejected; it was corrected before either reproduction. Initial native-dialog capture/input failures also remain separate from application acceptance. Independent evidence review confirmed the resulting screenshot states and persisted byte equality; screenshots alone do not capture the complete action sequence or transient state history.
+
+Candidate Windows GUI save/history/reopen, HTTP regression, broader affected suites and actual rendering acceptance remain outstanding. Raw local evidence is not yet a peer-consumable handoff; publish the consolidated evidence before integration.
+
+Scope boundary: contextual relationship forms retain the canvas while opening; successful Apply retains the existing explicit post-review navigation. The generic child-creation handler is tested for containment and allocation, but the separate architecture palette/performer workflow still offers creation kinds for the diagram layer. Thus an OA performer displayed in an SA Traceability view has no Add activity menu entry; this inherited limitation is not claimed repaired here.