Wasm-mvp is very simple, especially if you drop the floating point instructions. But WAMR supports a lot of extensions - https://github.com/bytecodealliance/wasm-micro-runtime?tab=r.... There is a garbage collector, jit, WASI, threads, debugger support etc.

My bad :)

EDIT I totally missed the context

I've tried using binaryen, and I've also tried emitting raw wasm by hand, and the latter was far easier. It only took ~200 lines of wasm-specific code.