I can understand the frustration coming from lack of rollback , but...
it was kinda messing with the whole mechanic of passing time and gaining items. People could just rollback whenever they got an event they didn't want.
I'm not sure about 'max' you refer to. But if I understand it right. I think Rollback function may cause some bugs for Time Mechanic. That why Hyao choose to remove this function from the game.
Still tho, what if we had rollback and Nameless removes that option during the 4th nightmare.. or completely removes it from our game.... that kind of fits his character.