A few small suggestions, mostly related to autosave feature.
If possible - make it so that autosave counter resets after saving manually? Currently when it ticks every 10 minutes related to how much that would be of in-game time, and even if you recently saved manually, it can override that save within a minute automatically. So if you're screwing something up and think you're safe, you might potentially get screwed over by the game.
Also, due to existence of a Nightmare achievement - I think it would be nice, if possible, to enact Meta Paranoia on player whenever they decide to climb their dumb ass inside the cremator, so frying yourself wouldn't end up with being autosaved in the middle of sick burns, potentially ruining the save file.
Additionally, reset function on a game safe would probably require some additional work. I've noticed that it is quite possible to reset your save to the day of 25, by which Ariral Treehouse is supposed to be complete, but neither arirals nor treehouse would be there, although you'd still have all ariral reputation if you didn't reset literally everything (tho I don't think there is an option to reset reputation) and arirals will keep interacting with you according to their reputation with you (brownies trail event still occurs, but now you can't get the doll if you stand at "loyal" rep). I suspect its due to items being reset, but I believe it would be fair to include the additional story-related builds and props into reset states, as this situation basically removes the ability to interact with arirals for the rest of the run, unless you reset your days further to when treehouse is yet to be built (funnily enough, it didn't reset the deer corpse from deer signal, however).