A month before the rewrite I was hitting soundness bugs on fairly trivial JS code. I remember right, under HMR re-exports of module variables caused a snapshot, and importers of the reexport saw stale values.

I reported it, watched robobun write an unhinged +300 -0 patch which quickly got LGTM'd and merged.

I hope now that we've moved past AGI and into the ASI era things are better.