I was just noting that the entire idea of the keyring was raised and discussed in that thread, not just the title topic. I'd agree, but I would think that this feature would be largely reserved for those maps with so many keys that they can be considered a keyhunt, or are otherwise massive. Also, the problem is the inventory clutter, not the tension. It could be possible to implement a key cycling delay based on an array that holds each key as they are added to the player's keyring. You select the keyring, use it on the door, you get a ~0.4 sec delay with a jingly/unlocking attempt sound until it opens. Once you use the key it gets whitelisted and works immediately.