diff --git a/packages/editor/src/components/editor/floating-action-menu.tsx b/packages/editor/src/components/editor/floating-action-menu.tsx
index 1f6a6280..0f4cdbc8 100755
--- a/packages/editor/src/components/editor/floating-action-menu.tsx
+++ b/packages/editor/src/components/editor/floating-action-menu.tsx
@@ -147,6 +147,7 @@ export function FloatingActionMenu() {
           duplicate.start = [duplicate.start[0] + 1, duplicate.start[1] + 1]
           duplicate.end = [duplicate.end[0] + 1, duplicate.end[1] + 1]
         } else if (node.type === 'roof') {
+          duplicateInfo.children = []
           duplicate = RoofNode.parse(duplicateInfo)
         } else if (node.type === 'roof-segment') {
           duplicate = RoofSegmentNode.parse(duplicateInfo)
@@ -160,6 +161,12 @@ export function FloatingActionMenu() {
         }
       } catch (error) {
         console.error('Failed to parse duplicate', error)
+        useScene.temporal.getState().resume()
+        return
+      }
+
+      if (!duplicate) {
+        useScene.temporal.getState().resume()
         return
       }
 
diff --git a/packages/editor/src/components/editor/selection-manager.tsx b/packages/editor/src/components/editor/selection-manager.tsx
index a4b74934..3d9ef80a 100755
--- a/packages/editor/src/components/editor/selection-manager.tsx
+++ b/packages/editor/src/components/editor/selection-manager.tsx
@@ -920,13 +920,13 @@ const EditorOutlinerSync = () => {
     outliner.selectedObjects.length = 0
     for (const id of idsToHighlight) {
       const obj = sceneRegistry.nodes.get(id)
-      if (obj) outliner.selectedObjects.push(obj)
+      if (obj?.parent) outliner.selectedObjects.push(obj)
     }
 
     outliner.hoveredObjects.length = 0
     if (hoveredId) {
       const obj = sceneRegistry.nodes.get(hoveredId)
-      if (obj) outliner.hoveredObjects.push(obj)
+      if (obj?.parent) outliner.hoveredObjects.push(obj)
     }
   }, [phase, previewSelectedIds, selection, hoveredId, outliner])
 
diff --git a/packages/editor/src/components/ui/item-catalog/catalog-items.tsx b/packages/editor/src/components/ui/item-catalog/catalog-items.tsx
index d2ef0b1c..a43aa21b 100755
--- a/packages/editor/src/components/ui/item-catalog/catalog-items.tsx
+++ b/packages/editor/src/components/ui/item-catalog/catalog-items.tsx
@@ -1578,3 +1578,8 @@ export const CATALOG_ITEMS: AssetInput[] = [
     },
   },
 ]
+
+export function getDefaultCatalogItem(category: string | null | undefined): AssetInput | null {
+  if (!category) return null
+  return CATALOG_ITEMS.find((item) => item.category === category) ?? null
+}
diff --git a/packages/editor/src/store/use-editor.tsx b/packages/editor/src/store/use-editor.tsx
index 73b83021..9f624144 100644
--- a/packages/editor/src/store/use-editor.tsx
+++ b/packages/editor/src/store/use-editor.tsx
@@ -21,6 +21,7 @@ import {
 import { useViewer } from '@pascal-app/viewer'
 import { create } from 'zustand'
 import { persist } from 'zustand/middleware'
+import { getDefaultCatalogItem } from '../components/ui/item-catalog/catalog-items'
 
 const DEFAULT_ACTIVE_SIDEBAR_PANEL = 'site'
 const DEFAULT_FLOORPLAN_PANE_RATIO = 0.5
@@ -344,6 +345,10 @@ export function selectDefaultBuildingAndLevel() {
   }
 }
 
+function getDefaultSelectedItemForCategory(category: CatalogCategory | null): AssetInput | null {
+  return getDefaultCatalogItem(category)
+}
+
 const useEditor = create<EditorState>()(
   persist(
     (set, get) => ({
@@ -365,7 +370,11 @@ const useEditor = create<EditorState>()(
           } else if (phase === 'structure') {
             set({ tool: 'wall', catalogCategory: null })
           } else if (phase === 'furnish') {
-            set({ tool: 'item', catalogCategory: 'furniture' })
+            set({
+              tool: 'item',
+              catalogCategory: 'furniture',
+              selectedItem: getDefaultSelectedItemForCategory('furniture'),
+            })
           }
         } else {
           // Reset to select mode and clear tool/catalog when switching phases
@@ -405,8 +414,15 @@ const useEditor = create<EditorState>()(
             } else if (phase === 'structure' && structureLayer === 'elements') {
               set({ tool: 'wall' })
             } else if (phase === 'furnish') {
-              set({ tool: 'item', catalogCategory: 'furniture' })
+              set({
+                tool: 'item',
+                catalogCategory: 'furniture',
+                selectedItem: getDefaultSelectedItemForCategory('furniture'),
+              })
             }
+          } else if (phase === 'furnish' && tool === 'item' && !get().selectedItem) {
+            const category = get().catalogCategory ?? 'furniture'
+            set({ selectedItem: getDefaultSelectedItemForCategory(category) })
           }
         }
         // When leaving build mode, clear tool
@@ -434,7 +450,17 @@ const useEditor = create<EditorState>()(
         })
       },
       catalogCategory: DEFAULT_PERSISTED_EDITOR_UI_STATE.catalogCategory,
-      setCatalogCategory: (category) => set({ catalogCategory: category }),
+      setCatalogCategory: (category) =>
+        set((state) => ({
+          catalogCategory: category,
+          selectedItem:
+            category !== null &&
+            state.phase === 'furnish' &&
+            state.mode === 'build' &&
+            state.tool === 'item'
+              ? getDefaultSelectedItemForCategory(category)
+              : state.selectedItem,
+        })),
       selectedItem: null,
       setSelectedItem: (item) => set({ selectedItem: item }),
       movingNode: null as
@@ -517,11 +543,23 @@ const useEditor = create<EditorState>()(
     }),
     {
       name: 'pascal-editor-ui-preferences',
-      merge: (persistedState, currentState) => ({
-        ...currentState,
-        ...normalizePersistedEditorUiState(persistedState as Partial<PersistedEditorState>),
-        ...normalizePersistedEditorLayoutState(persistedState as Partial<PersistedEditorState>),
-      }),
+      merge: (persistedState, currentState) => {
+        const mergedState = {
+          ...currentState,
+          ...normalizePersistedEditorUiState(persistedState as Partial<PersistedEditorState>),
+          ...normalizePersistedEditorLayoutState(persistedState as Partial<PersistedEditorState>),
+        }
+
+        return {
+          ...mergedState,
+          selectedItem:
+            mergedState.phase === 'furnish' &&
+            mergedState.mode === 'build' &&
+            mergedState.tool === 'item'
+              ? getDefaultSelectedItemForCategory(mergedState.catalogCategory ?? 'furniture')
+              : currentState.selectedItem,
+        }
+      },
       partialize: (state) => ({
         phase: state.phase,
         mode: state.mode,
diff --git a/packages/viewer/src/components/viewer/index.tsx b/packages/viewer/src/components/viewer/index.tsx
index cf00dd5e..bfbfdc96 100644
--- a/packages/viewer/src/components/viewer/index.tsx
+++ b/packages/viewer/src/components/viewer/index.tsx
@@ -110,6 +110,12 @@ const Viewer: React.FC<ViewerProps> = ({
         const renderer = new THREE.WebGPURenderer(props as any)
         renderer.toneMapping = THREE.ACESFilmicToneMapping
         renderer.toneMappingExposure = 0.9
+        // Awaiting init() is required when the browser falls back to the
+        // WebGL2 backend (Safari without the WebGPU flag, older Chrome on
+        // machines without a WebGPU device). In native WebGPU mode the
+        // init resolves almost instantly. Without this await, the first
+        // render throws "Renderer: .render() called before the backend is
+        // initialized" from the post-processing fallback path.
         await renderer.init()
         return renderer
       }}
diff --git a/packages/viewer/src/components/viewer/post-processing.tsx b/packages/viewer/src/components/viewer/post-processing.tsx
index 8daf68be..ef3fa646 100644
--- a/packages/viewer/src/components/viewer/post-processing.tsx
+++ b/packages/viewer/src/components/viewer/post-processing.tsx
@@ -117,6 +117,24 @@ const PostProcessingPasses = () => {
 
     hasPipelineErrorRef.current = false
 
+    // WebGPU availability check: SSGI, denoise, and RenderPipeline are all
+    // WebGPU-only APIs. When the browser falls back to WebGL2 (no
+    // `navigator.gpu`, or the device couldn't be created), building the
+    // pipeline either throws silently or produces a broken output where
+    // the scene renders for a few frames and then goes black as the retry
+    // loop fights the direct-render fallback path. Short-circuit here so
+    // `useFrame` uses the direct `renderer.render(scene, camera)` path
+    // exclusively and never attempts the TSL pipeline.
+    const hasWebGPU = typeof navigator !== 'undefined' && typeof navigator.gpu !== 'undefined'
+    if (!hasWebGPU) {
+      console.warn(
+        '[viewer] WebGPU unavailable — rendering without post-processing (SSGI, outlines, denoise).',
+      )
+      hasPipelineErrorRef.current = true
+      renderPipelineRef.current = null
+      return
+    }
+
     // Clear outliner arrays synchronously to prevent stale Object3D refs
     // from the previous project leaking into the new pipeline's outline passes.
     const outliner = useViewer.getState().outliner
@@ -263,15 +281,7 @@ const PostProcessingPasses = () => {
       }
       renderPipelineRef.current = null
     }
-  }, [
-    renderer,
-    scene,
-    camera,
-    hoverHighlightMode,
-    zoneLayers,
-    projectId,
-    pipelineVersion,
-  ])
+  }, [renderer, scene, camera, hoverHighlightMode, zoneLayers, projectId, pipelineVersion])
 
   useFrame((_, delta) => {
     // Animate background colour toward the current theme target (same lerp as AnimatedBackground)
diff --git a/packages/viewer/src/lib/merged-outline-node.ts b/packages/viewer/src/lib/merged-outline-node.ts
index 440535d1..f3617b35 100644
--- a/packages/viewer/src/lib/merged-outline-node.ts
+++ b/packages/viewer/src/lib/merged-outline-node.ts
@@ -600,9 +600,14 @@ export class MergedOutlineNode extends TempNode {
 
   private _buildCache(objects: Object3D[], cache: Set<Object3D>) {
     for (const obj of objects) {
-      obj.traverse((child: any) => {
-        if (child.isMesh || child.isSprite) cache.add(child)
-      })
+      if (!obj || !obj.traverse) continue
+      try {
+        obj.traverse((child: any) => {
+          if (child.isMesh || child.isSprite) cache.add(child)
+        })
+      } catch {
+        // Skip objects that were disposed or removed from the scene graph
+      }
     }
   }
 }