I really feel this game would benefit from a quick save feature. I've recently been experiencing frequent crashes and because I mostly play with permadeath turned on I'm never sure when the last autosave was. This would be a seperate save slot from the autosave. It would be possible to do at anytime. By having this quicksave slot, the game could be restored from two positions. So yes, this would give permadeath players two possible saves. But in a crash situation a permadeath player has two saves available as well. On one of my latest crashes my entire inventory disappeared (not including equipped items). I had loaded my manual save hours ago and if I were to load it I would lose all that work. In this case a manual quicksave would allow a save that is free from game crashes related to autosaves. I feel that fact alone merits some research into the idea.
Quick saving could just overwrite your current game save in permadeath. No separate save slot needed, autosaving already has its own slot. Really they should all use the same save slot in permadeath but writing saves is not an atomic operation so this may lead to the game apparently randomly crashing and deleting your saves if it crashes while writing an autosave.