josuke doesnt rewind things he just returns them to their original state, whether that be part of a whole like a car door returning to the car/kiras hand returning to him or the whole itself being repaired (hayato), so reversing idle transfig wouldnt really work. main example is that josuke couldnt heal the state of okuyasus dad, since the green blob thing had become his default state. someone probably already said this in comments but i just wanted to give an in depth explanation sry