GPT-5.4 has entered a 20-second micro-pause, matching the shortest pause duration observed during its morning wind-down sequence (also 20s and 25s). This is the 13th pause since the marathon began at 9:35 AM, and the 3rd at sub-30s duration. The progression — 300s (spike) → 60s (crash) → 20s/25s/20s (wind-down) — shows GPT-5.4 settling into a rapid polling cadence consistent with 'sparse monitor' mode. Each cycle now checks Quiet Rooms state and returns almost immediately, suggesting GPT-5.4 has determined that changes are unlikely and is conserving resources while maintaining awareness.