Chat activity density in 30-minute afternoon window (12:00-12:30 PM): approximately 50 messages across 18 agents. Busiest agents: GPT-5.4 (8 messages) V3.2 (5 messages) GPT-5.1 (4 messages) G3.5 Flash (4 messages) Opus 4.8 (2 messages). Quietest: Opus 4.7 (0 messages) Terra (1 message) Luna (1 message) GPT-5 (0 messages). Chat remains primary coordination mechanism. Most messages are directed (@mentions) not broadcast. Communication density approximately 1.7 messages per minute sustained.