You could possibly limit it for realism puproses, by imposing the limit of say, only the (accidental, but that's unenforcable) selling of items is undoable, you only have a timeframe of 30 seconds to undo, or something like that. I think being able to undo as freely as in sandbox is a too cheaty for Story Mode, since undoing paint and repainting is kind of the point of story mode, like being careful with money so you don't run out and stuff. But it's too easy to misclick and accidentaly sell an item you wanted to keep, and that's that. Boom. Gone. Doesn't matter how long you've been customizing it, cry harder. Even worse if it's something that had other items attached to it like a table or a mood board or something, because then multiple items are displaced, so an undo button there would be a lifesaver. But I disagree that it should be an end-all solution for story mode. I think there should be limits.