If you're that concerned about performance, though, aren't doing things like `.asyncJoin()` just going to eat up any potential gains by 1) wrapping the result in a Promise and 2) throwing the Promise back into the event/microtask queue? It seems like the transport would quickly become the bottleneck.
I'm also struggling to understand what tier of performance you're aiming for, since you're hoping to boost performance by using a Thread in JS when, in node, you can already code expensive computation in C++ and expose a binding back to JS (which to me makes more sense in the context of game design since that's basically what most already do with Lua--this would just be in reverse).