> How feasible would it be to use Clang or GCC on Windows?
clang seems to have a good Windows support and tries to the ABI compatible with MSC which is a must have to keep wheel package support (especially for the stable ABI, used by PyQt on Windows for example).
Moreover, there are ways to cross-build Python from another platform to Windows which can be convenient ;-)
I don't know the Windows ecosystem. Do people want to get VS debugger for example? Is clang compatible with the VS debugger?
See the discussion of 2014: "Status of C compilers for Python on Windows"
https://mail.python.org/archives/list/python-dev@python.org/thread/SYWDJ23AQDPWQN7HD6M6YCSGXERCHWA2/