I came here to suggest the very same thing. It is very difficult to ensure a unique label without some sort of incremented counter when burning many disks.
Making ImgBurn just remember labels between sessions would be a great first step. That would at least let people manually increment their labels.
The next step would be for ImgBurn to use some sort of string token to indicate a counter, and then increment the counter by one with each new disk or compilation.
It's a pretty simple and self-contained task really. Just saving and parsing a string between sessions.
