Changing a book doesn't immediately change the set of sentences you are studying. There are also likely issues in the order sentences are presented.
I'm open to ideas on how to handle this, i.e. if you are studying F2 and F3 and add F1, should it start adding sentences from F1 immediately or wait until you've finished F2/F3? Or should you be able to arrange the books in the order you want to study?
Changing a book doesn't immediately change the set of sentences you are studying. There are also likely issues in the order sentences are presented.
I'm open to ideas on how to handle this, i.e. if you are studying F2 and F3 and add F1, should it start adding sentences from F1 immediately or wait until you've finished F2/F3? Or should you be able to arrange the books in the order you want to study?