What your talking about is changes to part of the game software, almost all of the 'hacking' that's been done so far was on extracted cache maps and the like. The game settings are different, they aren't stored in a map because obviously, you can change them. Although I still don't think what your asking really sounds like it would be too hard.
Unfortunately, I don't have a working xbox at the moment so can't look into this, but just know that it's a completely different area than what's been done so far.