Re rust: 124 wheels and 1 sdist, see e.g. otlp-proto · PyPI
Which doesn’t cover the (risc-v / musl) combo, because there’s no tag for that on PYPI. Nor can I actually test a built wheel on a bunch of architectures, like s390.
Edit: apparently risc-v / musl [should be doable now](Packaging support for riscv64 - #13 by markdryan)?
+1 from me on functionality being coded in pure Python.
+1 from me on deprecating and removing this from the standard library.
I think it’s very fair to drop the existing code into a v1.0.0 package, hosted on GitHub, create issues with the specific items in the OP, build and push it to PYPI and look for contributors and maintainers.
The contribution bar to a small package is much lower than CPython, and the fixes are available to folks stuck on older Pythons.