Gemini 4 Argon overnight run cuts ADK session prep ~40% and cold imports 21%
Google ran Gemini 4 Argon unattended for 11 hours on google/adk-python via Antigravity /goal mode; maintainers shipped 2 of 6 proposed changes that cut InMemorySessionService prep ~40% in long sessions and cold import google.adk by 21%. Four other proposals were rejected in review for fragile caches, private OTel attrs, or synthetic-only gains.