Is any work being on tightening up the book syncing process?
When you assign a letter link set to a book, and then move through scripture, some books follow along flawlessly. But then there are other books (commentaries) that "sort of" follow along, and yet another set of books that don't follow along at all.
For example, I am in Ephesians:
the Faith Life Study Bible follows along perfectly.
The William Hendriksen commentary "sort of" follows along. Sometimes it just plops itself in the area 
And then others like the Ephesians Letter by Lewis Chafer and Albert Barnes Ephesians, Philippians and Colossians commentary don't even come close.
And there are others that I just gave up on because it was too much work trying to always bring them into sync with where I was.
I've been holding off saying anything because I thought maybe it was just something that was being worked on, but this has gone on for quite a long time.