I have two suggestions for features that would help me quite a bit.
1. Probably the simplest one to implement; a box below the A and B boxes that indicate how much time is marked in between A and B, in seconds and frames. So I don't have to do that math in my head.
2. The more complicated one; multiple cuts. I want to be able to load a file, mark a selection between A and B, put that selection in a list/queue, make more selections, and then output those selections into a single file.