diff --git a/open-questions.md b/open-questions.md
index 8f32a8f..cf7ed11 100644
--- a/open-questions.md
+++ b/open-questions.md
@@ -29,10 +29,16 @@ consistency" framing instead of broad review? The hypothesis: Sonnet's
 
 ## Medium Priority
 
-### Adversarial analysis ensemble (from Finding #29)
-Run GPT-5 and Opus sequentially — give Opus access to GPT-5's findings
+### ~~Adversarial analysis ensemble (from Finding #29)~~ → ANSWERED (Finding #35)
+~~Run GPT-5 and Opus sequentially — give Opus access to GPT-5's findings
 and ask it to critique and extend. Does the ensemble find more than either
-alone? Does Opus's system-level thinking complement GPT-5's exhaustiveness?
+alone? Does Opus's system-level thinking complement GPT-5's exhaustiveness?~~
+
+**YES.** Ensemble produces 56 findings vs 43 (GPT-5) or 28 (Opus) alone (30%
+improvement). Zero full disagreements — critique phase calibrates severity
+without discarding. Extension phase adds 13 genuinely new findings (4 High).
+The critique's structured assessment is more valuable than raw extensions.
+Cost: ~28% more tokens for 30% more coverage + prioritization.
 
 ### Reasoning effort parameter (from Finding #21)
 Reasoning effort (low/medium/high) had negligible effect on GPT-5's