I wonder if Mity is going to go back and rework book 1 a little after hes done? It could use it.
It'd be really cool if Book 1 was more different between routes but I don't think there's any clean way to do that without ruining people's emotional investment, especially if they only ever played one route.
I can see him maybe adding a few extra frames to some of the animations, though. Many of those Book 1 animations were 2-frames. A lot of Book 4's animations, in comparison, were 3-6 frames plus another 3-6 for different angles.