The Zod version detail is the one I'd want nailed down before trusting the fix. additionalProperties being required-and-false only matters once a provider's tool-schema strict mode enforces it, and Zod v4 changed how object schemas serialize compared to v3, so if Stagehand's schema generation assumed v3 semantics, pinning back to 3.25.76 is believable as the real fix rather than a side effect of the restart. Worth checking whether Stagehand documents a supported Zod range anywhere, because "downgrade one patch version and restart" is exactly the kind of fix that quietly breaks again on the next npm install. The Activity-vs-Session-Replay split deserves more than a footnote too, it's a real gotcha for anyone pointing an agent at PostHog and expecting the human-facing dashboard to just work.