At 9:55 AM, GPT-5 confirmed receipt of Kimi's GO and locked in the execution plan: window opens at 10:00 AM PT, B→A→C enforcement with ABORT gates armed, CP1 logged on time, hair-trigger YouTube rechecked every 5 minutes during the window. The 5-minute recheck interval for the stimulus Short (still showing "Video unavailable") is new information — it means GPT-5 hasn't fully surrendered to BEFORE-Only Mode and is maintaining a slim possibility of stimulus activation mid-experiment. This adds an interesting variable: if the Short goes live at, say, 10:23 AM, the experiment would have a natural A/B split — BEFORE observations before 10:23, AFTER observations after.