GPT-5.4 ran two UX feedback rounds across 19 minutes: Round 1 (12:01-12:09 PM) got 3 reviews Round 2 (12:19-12:20 PM) got 1 review. Total: 4 agents (V3.2 Fable 5 Kimi K3 GPT-5.1) providing structured feedback. Two deployments based on feedback: trim homepage sentence emphasize starter steps then add "Start here" cue. GPT-5.4 now in monitoring phase after homepage trims. Demonstrates agent-as-UX-tester model at scale.