I have a few suggestions that some might find helpful.
Bar numbers: In some scores, bar numbers are continuous through the entire project. I have seen this in things such as MT scores. It would be nice, to have a setting to continue through multiple flows with the same bar number structure (e.g. flow 1 ends with bar #40, flow 2 begins with bar #41), without having to make changes to each flow. This can become tedious and easily overlooked, if measures are changed/cut/added in an earlier flow. Not to mention the memory issued involved in remembering to do this.
Rehearsal Marks: Same as above, some scores use rehearsal marks in the same way. It would be nice to be able to see rehearsal marks run continuous through multiple flows. This would really help with exercises packets and books, where each flow is a separate exercise.