I have looked at Prepack! I was wondering if it would be revisited. I certainly understand that lack of confidence, though I think I'd worried more about the false negative: something should be available to the client, but for whatever reason the compiler couldn't identify it. That said, I think tooling could go a long way to address the false positive. For example, in Next.js dev mode, there's an indicator that says whether a page can be statically rendered. If there were tools that said "we've automatically marked this component for the client bundle" and allowed the dev to manually opt out if they're sure the component shouldn't be sent to the client, it's still nice to have for the non-pathological case.

Anyway, thanks for filling in more detail!