How to enable quicksave (read the warning)

[Jetsetlemming]

You don't get much extra difficulty from not being able to save anywhere in Penumbra. You've got automatic healing just from standing around, there are few enemies, and the main difficulty is from puzzles and enviromental hazards rather than enemies anyway.
However, quicksaving CAN end up with you saving in situations you can't get out of, such as in the middle of a chase scene when you don't have enough time to escape or something along those lines.
I'd say make it a full fledged feature that a) turns off on hard difficulty by default, and b) Turns off ingame during special situations like chase scenes and whenever you're near an enemy. Basically whenever you hear the scary music, you can't save.