This looks very nice! I wonder if it might be easy(ish) to wrap it as a plug-in for asdf? There's already an opam/ocaml plug-in - but from comments here it sounds like it might be possible to write a wrapper similar to the ruby plug-in that re-uses a lot of the tooling for rbenv/build. (as does the rust plug-in, and others)

https://github.com/asdf-vm/asdf