Okay, so the way doors currently work, if they're not wired up, you can just interact with them to open and close them. However, if they are wired, the only way to open or close them is with signals to that input. But, what if we want to be able to open and close the door via normal interaction, but still be able to lock it from one side so that it cannot be opened? This idea would put a second input on doors. The second input shifts the door between Auto and Manual modes. Auto Mode works as usual--the door opens or closes with a signal to the default input. Manual Mode disregards the state of the default input, and the door can be manually opened or closed as if it was unwired. EDIT: Just realized this is technically already doable with buttons, a switch, and an AND Gate.
This idea made me think, they should add locks or keypads to dungeons, and to either collect the key or find the password you would have to complete missions for npcs on that planet. They could also be craft able so you can lock your own doors. Thank you for inspiring me!