So, I was a busy little programmer and wrote a UV transfer program. It's not very user-friendly yet. You have to isolate the bits with the donor UVs into their own .obj file and run the whole thing from the commandline. But it works, and it let me fix the problem with the non-matching foot and toecap UVs.

Will upload the new version tomorrow.

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