[the_duke]

No comment on the other points (I also prefer Wasmtime), but:

I believe the linking proposal is dead for now and replaced by the component model: https://github.com/WebAssembly/component-model

The wasmtime implementation is in progress.

[Conlectus]

Yep, I'm aware ("ahead of its replacement"), but in the mean time it really helps to have something that just solves the "take these two modules and merge their functions" problem.