diff --git a/src/main/kotlin/com/gzzn/omms/msgexchange/infra/stub/StubRepositories.kt b/src/main/kotlin/com/gzzn/omms/msgexchange/infra/stub/StubRepositories.kt
index b1b2db9..19c3517 100644
--- a/src/main/kotlin/com/gzzn/omms/msgexchange/infra/stub/StubRepositories.kt
+++ b/src/main/kotlin/com/gzzn/omms/msgexchange/infra/stub/StubRepositories.kt
@@ -54,9 +54,9 @@ class StubPipelineLock : PipelineLockRepository {
     override fun lock() = Unit
 }
 
+/** 内存版 PROC_STATE：入队幂等，写终态时一并写下回填待办。 */
 @Singleton
 @Requires(property = "msgx.stubs", value = "true")
-/** 内存版 PROC_STATE：入队幂等，写终态时一并写下回填待办。 */
 class StubProcState(private val clock: Clock = Clock.systemUTC()) : ProcStateRepository {
     val rows = linkedMapOf<Long, ProcState>()
     val bound = linkedMapOf<String, Long>()
@@ -186,6 +186,7 @@ class StubProcState(private val clock: Clock = Clock.systemUTC()) : ProcStateRep
 
     override fun findBackfillDue(now: Instant, overdueBefore: Instant, limit: Int): List<BackfillDue> =
         rows.values
+            .asSequence()
             .filter { it.state.isTerminal() && it.backfillAt == null && it.backfillAbandonedAt == null }
             // 超期判据是本地入队时间，与 JDBC 实现保持一致（不用库方时钟的 receivedAt）。
             .map { it to (it.enqueuedAt?.let { e -> e < overdueBefore } ?: false) }
@@ -194,6 +195,7 @@ class StubProcState(private val clock: Clock = Clock.systemUTC()) : ProcStateRep
             .sortedWith(compareBy({ it.first.backfillAttempts }, { it.first.msgId }))
             .take(limit)
             .map { (row, overdue) -> BackfillDue(row.msgId, row.backfillAttempts, overdue) }
+            .toList()
 
     override fun hasAny(): Boolean = rows.isNotEmpty()
 
@@ -251,11 +253,12 @@ class StubMsgEvents : MsgEventRepository {
      */
     private fun upsertSchd(e: MsgEvent): Long {
         val existing = rows.values.firstOrNull { it.target == Targets.KAFKA_SCHD && it.partitionKey == e.partitionKey }
-        val accepted = existing == null ||
-            e.stateVersion > existing.stateVersion ||
-            (e.stateVersion == existing.stateVersion && e.eventType == EventType.TOMBSTONE && existing.eventType != EventType.TOMBSTONE)
-        if (!accepted) return existing!!.eventId!!
-        existing?.let { rows.remove(it.eventId!!) }
+        if (existing != null) {
+            val accepted = e.stateVersion > existing.stateVersion ||
+                (e.stateVersion == existing.stateVersion && e.eventType == EventType.TOMBSTONE && existing.eventType != EventType.TOMBSTONE)
+            if (!accepted) return existing.eventId!!
+            rows.remove(existing.eventId!!)
+        }
         val id = ids.incrementAndGet()
         rows[id] = e.copy(
             eventId = id, state = EventStatus.PENDING, attempts = 0, nextAttemptAt = null,
@@ -327,7 +330,7 @@ class StubFlightState : FlightStateRepository {
         }
         val main = FlightMainRow(
             flid = snapshot.flid,
-            operationDay = snapshot.operationDay ?: existing?.operationDay,
+            operationDay = snapshot.operationDay,
             state = snapshot.state,
             stateVersion = snapshot.stateVersion,
             lastMsgId = msgId,
@@ -342,7 +345,7 @@ class StubFlightState : FlightStateRepository {
         val main = mains[flid] ?: return false
         if (main.state != FlightState.ACTIVE) return false
         mains[flid] = main.copy(state = FlightState.DELETED, stateVersion = main.stateVersion + 1, lastMsgId = msgId, updatedAt = now)
-        snapshots[flid] = (snapshots[flid] ?: return true).copy(state = FlightState.DELETED, stateVersion = main.stateVersion + 1)
+        snapshots[flid] = snapshots[flid]!!.copy(state = FlightState.DELETED, stateVersion = main.stateVersion + 1)
         return true
     }
 
@@ -350,7 +353,7 @@ class StubFlightState : FlightStateRepository {
         val main = mains[flid] ?: return false
         if (main.state != FlightState.DELETED) return false
         mains[flid] = main.copy(state = FlightState.ACTIVE, stateVersion = main.stateVersion + 1, lastMsgId = msgId, updatedAt = now)
-        snapshots[flid] = (snapshots[flid] ?: return true).copy(state = FlightState.ACTIVE, stateVersion = main.stateVersion + 1)
+        snapshots[flid] = snapshots[flid]!!.copy(state = FlightState.ACTIVE, stateVersion = main.stateVersion + 1)
         return true
     }
 
@@ -450,9 +453,9 @@ class StubReqTrack : ReqTrackRepository {
     }
 }
 
+/** 内存版共享信箱：可以模拟上游写入、库方清除，并记录哪些行被打上了处理标记。 */
 @Singleton
 @Requires(property = "msgx.stubs", value = "true")
-/** 内存版共享信箱：可以模拟上游写入、库方清除，并记录哪些行被打上了处理标记。 */
 class StubInbox(private val clock: Clock = Clock.systemUTC()) : CminmsgInboxRepository {
     val raws = linkedMapOf<Long, String>()
     private val received = linkedMapOf<Long, Instant>()