diff --git a/frontend/src/features/layout/LayoutGrid.chat.test.tsx b/frontend/src/features/layout/LayoutGrid.chat.test.tsx
index ff41c1dc..5091bab6 100644
--- a/frontend/src/features/layout/LayoutGrid.chat.test.tsx
+++ b/frontend/src/features/layout/LayoutGrid.chat.test.tsx
@@ -182,7 +182,7 @@ describe("LayoutGrid custom agent CLI (#147)", () => {
     expect(screen.getAllByText(/mock-attachment.txt/).length).toBeGreaterThan(0);
   });
 
-  it("keeps the target announcement overlay visible in custom mode while busy (#232)", async () => {
+  it("keeps custom CLI visible while busy and locks only the composer (#247)", async () => {
     const gateways = await seeded(structuredProfile);
     const layout = gateways.layout as MockLayoutGateway;
     const workState = gateways.workState as MockWorkStateGateway;
@@ -218,8 +218,14 @@ describe("LayoutGrid custom agent CLI (#147)", () => {
     renderGrid(gateways);
 
     expect(await screen.findByTestId("custom-agent-chat-view")).toBeTruthy();
-    expect(await screen.findByTestId("target-announcements-overlay")).toBeTruthy();
-    expect(screen.getByText("Travaille sur une demande de Main.")).toBeTruthy();
+    expect(screen.queryByTestId("target-announcements-overlay")).toBeNull();
+    expect(screen.getByText("Busy · Main")).toBeTruthy();
+    await waitFor(() =>
+      expect(screen.getByLabelText(/message CLI custom/)).toHaveProperty(
+        "disabled",
+        true,
+      ),
+    );
   });
 
   it("renders requester-side delegation fallback in custom mode after remount (#232)", async () => {
@@ -265,13 +271,13 @@ describe("LayoutGrid custom agent CLI (#147)", () => {
     const view = renderGrid(gateways);
 
     expect(await screen.findByTestId("custom-agent-chat-view")).toBeTruthy();
-    expect(await screen.findByText("Délégation en cours.")).toBeTruthy();
+    expect(await screen.findByText("Worker attend Architect")).toBeTruthy();
 
     view.unmount();
     renderGrid(gateways);
 
     expect(await screen.findByTestId("custom-agent-chat-view")).toBeTruthy();
-    expect(await screen.findByText("Délégation en cours.")).toBeTruthy();
+    expect(await screen.findByText("Worker attend Architect")).toBeTruthy();
   });
 
   it("persists custom CLI composer height per layout cell", async () => {
diff --git a/frontend/src/features/layout/LayoutGrid.tsx b/frontend/src/features/layout/LayoutGrid.tsx
index 196047a5..c99802f3 100644
--- a/frontend/src/features/layout/LayoutGrid.tsx
+++ b/frontend/src/features/layout/LayoutGrid.tsx
@@ -1561,11 +1561,10 @@ function LeafView({
           </div>
         )}
         {/* F3 (ticket #4): while another agent is talking to THIS agent (target),
-            an availability veil showing its live réflexions. Driven by the target's
-            busy state (agentBusyChanged + read-model hydration), never by the raw
-            PTY — it retracts at idle even when a turn ends without a completion
-            event. Self-guards on `active` (busy) and renders null otherwise. */}
-        {!modelServerOverlay && agentId != null && (
+            an availability veil showing its live réflexions. Native TUI cells
+            need the full-cell guard; custom CLI cells keep the canonical busy
+            badge and composer lock only, matching their normal chat turn flow. */}
+        {!modelServerOverlay && cellMode !== "custom" && agentId != null && (
           <TargetAnnouncementsOverlay
             projectId={projectId}
             agentId={agentId}