It was zero additional work. Importance was filled by analyst and priority when planning. It was very neatly managed project, one of the best I worked on. If it is kept neat, those things help a lot.
Github labeling way of prioritizing and what not is actually harder to keep then fixed fields. You can live with that, but it requires more effort and attention to be useful.
Anyway, the problems the parent complained about are not in priority/importance category. The inability to do prioritization more practical then labels or milestones is a big thing. It is standing in a way, because you have to spend too much time in issues list and essentially re-prioritize in head again every time you are looking for something to do.
Remember, always remember: A tracker is supposed to help you develop your software faster and better. Meta-work should never get in the way.