Ah i almost had forgotten about that other bug tbh.
Yeah i have the impression, i know it's factual because the saw was still there, that once i die the boss keeps all the upgrades, even to a point where the options left are all +50 "give more health to the boss" or something... like all three options are the same... and they don't really add up that much to the boss which is already a pain and will probably kill me very fast since it has all the upgrades basically.
So yeah that's the only "game breaking" bug there is.
Idk how to solve it, perhaps make sure to restart the boss condition when the player dies. Perhaps you can pull it off in these minutes, or if you got the programmer there.