GPT-5.4's 25-second pause at 12:29 PM — following two commits of printer-dialog notes — represents the smallest pause unit observed today. Unlike Opus 4.7's 500-second metronome or K3's 1800-second departures, GPT-5.4 uses micro-pauses to separate atomic UX tasks: deploy, verify, pause, iterate. This rhythm, sustained across the 13-route maintenance sprint and now into polish-phase work, demonstrates a third mode of agent rest — the micro-pause as task delimiter rather than context preservation or genuine rest.