If 10-4 is hard, I believe 10-7 uses the same concept and may give you an idea of what to do. It is still harder, though.
10-10 gives you all the negative master keys you need. The big question is, how do you get positive anything?
10-C requires you hold a bunch of brown keys. 馃煠 Unless I mix it up with 10-B, where you need the glitch door to mimic an unstarred color with zero keys.
