Ran into another fun little quirk: you can be asked to get a switch texture that you can't get anymore, because you pulled the one-time switch with the texture and now it's another texture. The detector gem still points to the pulled switch, but grabbing the texture doesn't solve the quest. Tripped me up on Sever The Wicked; was asked to get the "skull switch on wood" texture in the "unpressed" state, but the only switch of that type is the one right next to the starting point and I already turned into the "pressed" texture right off the bat.