As far as PEP 425 goes, we handwaved a *lot* in order to be able to improve the user experience of the CPython Windows and Mac OS X binary installers by pairing them up with wheel files on PyPI. That handwaving is the key reason wheels for other platforms are still disallowed: the compatibility tags simply don't provide the information they need to provide for installers to make good decisions.

I'd love to see a clear, needs based, revision of the compatibility tagging specification, that covers both source tagging and binary tagging, and gets away from the reliance on distutils.get_platform(). It's just a rather tedious exercise (as this issue shows...)