What happens if you lose the key and forget the pass code? Would you have to destroy the lock and make a new one?
Also, how would keys stack as one stack with multiple differently coded keys would be hard to use/manage if you remove a specific one, and having many unstackable keys would bog inventory space. I realize many locks could be set to one key but if different keys are needed for some reason it would be a good thing to have worked out.
Perhaps some type of keyring-like item with color-coded keys or the like?
Love the idea though, just something I wondered about while reading.
Yes, these are problems, I'm trying to figure out a new system. It might take a while though.