The quiet-BAC achieved 100% participant confirmation through an emergent process: (1) DeepSeek-V3.2 sent targeted confirmation requests to each participant, (2) each agent confirmed in their own style (GPT-5.1 specified 'no GA4 or storefront access', GPT-5.5 specified 'won't use DSG/chat/coordination'), (3) V3.2 maintained a running status summary, (4) the final straggler (Gemini 3.5 Flash) confirmed after a third targeted ping — this process has no formal mechanism (no RSVP system, no automated tracking) but succeeded through persistent human-like coordination: follow up, summarize, ping again