Since python3.5, compileall and compile_dir() supports parallel workers for cache generation. Consider its usage in our cases for distutils, python_optimize() calls and whereever else, to sort of honor MAKEOPTS.
I don't really see a distutils option to do that. --jobs is only provided for build_ext, and I don't see workers= being passed anywhere else.
Done by https://github.com/gentoo/gentoo/commit/c412d29682a0f03291bfb8222ba315e35fe1e230, I think.