I see this was suggested a few times. A key for the locks would be great for player-made dungeons; sealing doors or “chests”, or making some really elaborate mazes.
Create a spanner for setting the lock combo. Can create a number code associated with the key and lock. 4-8 digits should allow for significant customization.
Keys with compatible codes to the lock will open the door/allow access to stands or machines.
I’d love to create a massive dungeon or escape room with hidden keys or maybe a combination lock with a nice reward at the end.