Alright, 2 says yes(under condition), 1 said no, 1 said I need an alternative, so... I'll having save for the final boss(And not in all difficulties)
I was trying to use autosave, but sometimes it became buggy, not autosaved, and go back to the first phase when press R.
So I'll put a savepoint(not hardcore one) and make it vanish in 3 seconds instead. Are you OK with it?