diff --git a/internal/cloud/workbench-kafka-refresh-handoff.test.ts b/internal/cloud/workbench-kafka-refresh-handoff.test.ts
index 4c97719f..ffdf35a3 100644
--- a/internal/cloud/workbench-kafka-refresh-handoff.test.ts
+++ b/internal/cloud/workbench-kafka-refresh-handoff.test.ts
@@ -41,7 +41,7 @@ test("retention handoff replays once, deduplicates overlap and late pre-barrier
     "buffered-live:4:hwlab:evt_0_4",
     "connected:1"
   ]);
-  assert.deepEqual(summary.counts, { matched: 3, replayed: 3, buffered: 3, bufferedDelivered: 2, liveDelivered: 0, deduplicated: 1, resumeSkipped: 0 });
+  assert.deepEqual(summary.counts, { matched: 3, filteredNonHwlab: 0, replayed: 3, buffered: 3, bufferedDelivered: 2, liveDelivered: 0, deduplicated: 1, resumeSkipped: 0 });
 
   publishLive(record(2).value, transport(2));
   publishLive(record(5).value, transport(5));
@@ -101,6 +101,29 @@ test("retention emits handoff before buffered live flush and connected live", as
   assert.deepEqual(phases, ["replay:0", "replay:1", "handoff", "buffered-live:2", "live"]);
 });
 
+test("unscoped observer filters legacy non-HWLAB records without weakening scoped handoff", async () => {
+  let publishLive: any = null;
+  const delivered: string[] = [];
+  const legacy = { ...record(0), value: { schema: "platform-infra.kafka.shadow-produce.v1", eventId: "legacy-smoke" } };
+  const handoff = createWorkbenchKafkaRefreshHandoff({
+    allowUnscoped: true,
+    liveBufferLimit: 4,
+    subscribeLive(listener: any) { publishLive = listener; return () => {}; },
+    async queryRetention() {
+      publishLive({ schema: "platform-infra.kafka.shadow-produce.v1", eventId: "legacy-live" }, transport(2));
+      return queryResult([legacy, record(1)], [{ partition: 0, startOffset: "0", endOffset: "2" }]);
+    },
+    async deliverEvent(envelope: any) { delivered.push(envelope.eventId); return true; },
+    async deliverConnected() { return true; }
+  });
+
+  const summary = await handoff.start();
+  assert.deepEqual(delivered, ["hwlab:evt_0_1"]);
+  assert.equal(summary.counts.matched, 2);
+  assert.equal(summary.counts.filteredNonHwlab, 2);
+  assert.equal(summary.counts.replayed, 1);
+});
+
 test("retention handoff fails closed on a pre-barrier live gap", async () => {
   let publishLive: any = null;
   const handoff = createWorkbenchKafkaRefreshHandoff({
diff --git a/internal/cloud/workbench-kafka-refresh-handoff.ts b/internal/cloud/workbench-kafka-refresh-handoff.ts
index 4d6dd614..5a89b199 100644
--- a/internal/cloud/workbench-kafka-refresh-handoff.ts
+++ b/internal/cloud/workbench-kafka-refresh-handoff.ts
@@ -34,6 +34,7 @@ export function createWorkbenchKafkaRefreshHandoff(options = {}) {
   let pendingLiveDeliveries = 0;
   const counts = {
     matched: 0,
+    filteredNonHwlab: 0,
     replayed: 0,
     buffered: 0,
     bufferedDelivered: 0,
@@ -99,7 +100,12 @@ export function createWorkbenchKafkaRefreshHandoff(options = {}) {
   }
 
   function onLiveEnvelope(envelope, transport) {
-    if (phase === "closed" || phase === "failed" || !envelopeMatchesScope(envelope, sessionId, traceId)) return;
+    if (phase === "closed" || phase === "failed") return;
+    if (allowUnscoped && envelope?.schema !== "hwlab.event.v1") {
+      counts.filteredNonHwlab += 1;
+      return;
+    }
+    if (!envelopeMatchesScope(envelope, sessionId, traceId)) return;
     if (phase !== "live") {
       if (bufferedLive.length >= liveBufferLimit) {
         fail(handoffError("workbench_kafka_refresh_live_buffer_overflow", "Kafka refresh live buffer exceeded its YAML-owned capacity before handoff.", phase, { liveBufferLimit }));
@@ -186,6 +192,10 @@ export function createWorkbenchKafkaRefreshHandoff(options = {}) {
     const normalized = [];
     for (const record of records) {
       const envelope = record?.value;
+      if (allowUnscoped && envelope?.schema !== "hwlab.event.v1") {
+        counts.filteredNonHwlab += 1;
+        continue;
+      }
       if (!envelopeMatchesScope(envelope, sessionId, traceId) || envelope?.schema !== "hwlab.event.v1") {
         throw handoffError("workbench_kafka_refresh_scope_mismatch", "Kafka retention query returned an envelope outside the authorized scope.", phase);
       }