It would be nice to have some kind of indication that there are unread chapters in the branch that reader chooses to read. I mean... Let's say we have a story that splits in two halves right from the beginning. Reader read one half and than comes back to the introduction page and sees something like Option A Option B (some kind of mark that this choice includes unread chapters down the line) It allows reader to read the whole story without checking the story map for unread chapters. Also, it gives a good opportunity to reread the story if it has some additions in some of its branches
That won't work for linked chapters and for game mode. In general, you'd need to load all data from all or at least a lot of descendant chapters. Though I could imagine marking the chapter answers depending on their read/update status, similar to the markings on the story map.
