Is there any reason, once a key is used, why it should stick around? I'm not aware of any situation in which you can re-lock something in BG3. Are people going back through their album full of old keys, thinking about the doors and chests that they opened, and reliving the glory days?

It would be really nice to get rid of some of this clutter. It feels like keys should go onto a key ring when you find them and then they should just disappear when they are no longer relevant. Usually this means they would go away when they have been used. You could argue that they should also go away when you finish an act and can no longer return to the thing that they unlock. Either way, it would help to clean things up.