Currently, nothing respawns and there are no random encounters. So anything but the current model is just asking for devs to waste their resources for players to waste their time. You can already manually walk through empty rooms back to the surface if you want pointless travel time.
There is at least one situation I ran into where getting to my camp should have been impossible. I was in the goblin holdout and just killed the goblin leaders and didn't know how to get out yet. Going through the front door lead to a fight with the rest of the goblins. I was still able to leave, camp, and come back as if nothing was stopping me though.
