Keeping track of active settings...
I think that we could all agree that one of the key factors in how effective using Duolingo is has to do with what settings are turned on during lessons.
With that said, it'd be great to know what settings students have on when they do the exercises, and have that reflected somehow in the dashboard next to the lessons completed (assuming you track which settings are activated).
The transcription exercises for me are the most important and the speaking exercises are also very useful. A student with both of those settings on is getting a much richer experience than a student who has turned them off.