To quote myself:

Quote - I wasn't originally planning to make the UVs match precisely, but I agree that it would make texturing much easier. I'll see what I can do.

Yep! That's one of those things that sound easy and should be easy, but in practice, with the tools at hand, turn out to be incredibly painful. So I'll leave that for now and see if I can fix it later using my "alternate UVs conversion" idea. I'll put the new mesh with the added toecaps in my file locker once I've done some final cleanups, and if someone with better tools, more experience of more patience would like to try their hands, they are very welcome.

-- I'm not mad at you, just Westphalian.