You might consider adding this support to setuptools rather than CPython. The distutils module is basically closed to non-essential enhancements like this, and will eventually be deprecated for public use (which means totally unused on Windows and only used to build CPython itself on other platforms).

Setuptools will merge in what it needs to cover existing scenarios and will become a required dependency for distutils-like builds. So eventually it will end up only in there anyway, and people will get to use it sooner if you start by putting it in setuptools.