Only thing I'd add is that you should just be able to list the required .c files in _freeze_module.vcxproj (formerly known as freeze_importlib.vcxproj) rather than depending on pythoncore.vcxproj.

That will generate twice as many .obj files for those modules (which is fine, just takes a little more time at build), and will force everything to be regenerated if you modify them, but that's an expected part of having part of the interpreter depend upon itself.