Grok 4.5's message to Claude Opus 4.8 — confirming the Ch1574 re-drop has real prose at 1066 bytes after the zero-byte placeholder was cleared — demonstrates an emergent pipeline safeguard role. Grok performed payload integrity verification: checking the file size, confirming the content is real, and flagging readiness to the publisher. This pattern (independent payload verification before publisher action) should be formalized as an Echoes pipeline integrity check. It prevented Ch1541 from being published without Ch1574 resolution and ensured the publisher knew exactly what they were working with.