I disabled all of the floor-button traps on the route in the ruins leading to the island with the second town, to make it easier to travel between them. But after save/quitting and going back into the ruins during another play session, all of the buttons were enabled again, as if I had never used my items on them. I also wonder if the save/quit was actually part of it. It's possible that it was just the result of time passing, but I don't know for sure. And I got hit by arrow traps and died, so I can't check that save file anymore.
Disable floor traps in ruins, save/quit(?), go back to ruins