diff --git a/crates/rrt-runtime/src/smp.rs b/crates/rrt-runtime/src/smp.rs
index ebb4dc1..f72e926 100644
--- a/crates/rrt-runtime/src/smp.rs
+++ b/crates/rrt-runtime/src/smp.rs
@@ -9432,6 +9432,26 @@ fn parse_event_runtime_collection_summary_with_tag_width(
             .collect::<Vec<_>>();
         trigger_kinds_present.sort_unstable();
         trigger_kinds_present.dedup();
+        let mut mutation_candidate_record_indexes = records
+            .iter()
+            .filter(|record| {
+                record.grouped_effect_rows.iter().any(|row| {
+                    opcode_reaches_world_apply_compact_runtime_effect_dispatch_strip(row.opcode)
+                })
+            })
+            .map(|record| record.record_index)
+            .collect::<Vec<_>>();
+        mutation_candidate_record_indexes.sort_unstable();
+        mutation_candidate_record_indexes.dedup();
+        let mut mutation_candidate_opcodes = records
+            .iter()
+            .flat_map(|record| record.grouped_effect_rows.iter().map(|row| row.opcode))
+            .filter(|opcode| {
+                opcode_reaches_world_apply_compact_runtime_effect_dispatch_strip(*opcode)
+            })
+            .collect::<Vec<_>>();
+        mutation_candidate_opcodes.sort_unstable();
+        mutation_candidate_opcodes.dedup();
         let mut control_lane_notes = Vec::new();
         if nondirect_compact_record_count != 0
             && nondirect_compact_record_count == nondirect_compact_records_missing_trigger_kind
@@ -9446,6 +9466,16 @@ fn parse_event_runtime_collection_summary_with_tag_width(
                 trigger_kinds_present
             ));
         }
+        if !mutation_candidate_record_indexes.is_empty() {
+            control_lane_notes.push(format!(
+                "records with grouped opcodes already in the 0x00431b20 mutation strip = {:?}",
+                mutation_candidate_record_indexes
+            ));
+            control_lane_notes.push(format!(
+                "0x00431b20 mutation-strip opcodes present in decoded grouped rows = {:?}",
+                mutation_candidate_opcodes
+            ));
+        }
 
         return Some(SmpLoadedEventRuntimeCollectionSummary {
             source_kind,
@@ -9480,6 +9510,10 @@ fn parse_event_runtime_collection_summary_with_tag_width(
     None
 }
 
+fn opcode_reaches_world_apply_compact_runtime_effect_dispatch_strip(opcode: u8) -> bool {
+    matches!(opcode, 0x04..=0x08 | 0x0d | 0x10..=0x13 | 0x16)
+}
+
 fn try_parse_nondirect_event_runtime_record_summaries(
     records_payload: &[u8],
     records_payload_offset: usize,
@@ -22145,6 +22179,14 @@ mod tests {
         assert!(summary.control_lane_notes.iter().any(|line| {
             line.contains("all compact non-direct rows currently decode row bodies only")
         }));
+        assert!(summary.control_lane_notes.iter().any(|line| {
+            line.contains(
+                "records with grouped opcodes already in the 0x00431b20 mutation strip = [0]",
+            )
+        }));
+        assert!(summary.control_lane_notes.iter().any(|line| {
+            line.contains("0x00431b20 mutation-strip opcodes present in decoded grouped rows = [4]")
+        }));
         let record = summary
             .records
             .first()
diff --git a/docs/rehost-queue.md b/docs/rehost-queue.md
index 092f446..4dbb38b 100644
--- a/docs/rehost-queue.md
+++ b/docs/rehost-queue.md
@@ -252,6 +252,11 @@ Working rule:
     `control_lane_notes`; real `War Effort.gmp` output currently shows `24/24` compact non-direct
     rows still missing decoded trigger kind, which narrows the next owner question to the
     non-row-body control lane rather than the compact row framing itself
+  - the same probe now narrows the candidate runtime-effect set too:
+    it reports which decoded records already carry grouped opcodes in the grounded
+    `0x00431b20` mutation strip; real `War Effort.gmp` currently narrows that to record indexes
+    `[1, 9, 12, 13, 14, 15, 16, 17, 22]`, all through opcode `4`, so the next pass can focus on
+    that smaller subset instead of the full 24-row compact collection
   - the concrete owner strip above that bundle is grounded now too:
     `0x00433060` is the direct non-direct serializer loop that writes `0x4e99/0x4e9a/0x4e9b`,
     calls `0x00430d70` per live collection row, and sits beside the sibling `0x00433130` size/load