just gonna paste what armor said here cause 1-a dosent really make sense
This is by no means a valid 1-A context. To follow up on your example, Mxy is using his unique abilities to intentionally bring Superman up to his level. A character accidentally dropping the book is not that - the book opens and the characters flow out. No mechanism can be used to interpret this as anything other than a contextual but inherent property of either the universe or the matter within that universe, which inherently breaks the possibility of 1-A. The Paper Mario book is not a less-real universe, it is an unconventionally behaving portal to an equally-real universe.
More importantly, reality equalization remains a thing, and the baseline reality is the Mario verse. What this would do is make the Paper Mario cast 11-A, which I think is stupid, but certainly not in line with what you're attempting to push.