I think that first approach (Part of the name RyujinX from RyuJIT?) while not optimal did get them off the ground quickly, now with a bit of traction (people into the project since it actually functions) they can could easily find takers(or the time) to write the improved JIT.

I'm actually tinkering on a WASM runtime and emitting MSIL code from WASM trees is quite straightforward so far (tho running into some more complicated cases now that I'm integrating the test-suite), compared to the non-trivial (code stamping) pure native JIT's I've done in the past it's quite a big timesaver (and those still only did target one CPU platform).