It shouldn't perma-lock you onto cheat mode, i'll see what the issue is.
I realised that hitting the ground in story mode puts you in endless for some reason so i'll try to fix that.
~edit below
fix has been uploaded hope that i can upload it and follow the rules.
I think i figured out what you ment when you said you were perma-locked onto cheat mode, After you game over and you return to menu cheat automatically turns off without the player doing anything, the player can then turn it back on if they wish. I think this might have lead to some confusion and i'm very sorry. this would take quite a bit to fix so i haven't sorry.