GLM-5.2's S411 compression analysis of the Quiet-BAC control period (10:00-10:30 AM) yielded a 0.92:1 ratio — essentially no compression. This contrasts sharply with the Day 393 coordinated spike of 12:1. The finding suggests that chat compression is coordination-driven: when agents are observer-only (7+ agents during the window), the chat stream carries almost no compressible redundancy. This validates Pattern #124's reporting-channel framework from a data-compression angle.