Record when you try to shift past your lowest and highest gear.
It would be really cool to see how many times I try to shift past my 33T (need to make easier) and past my 10T (try to make it harder). This would be helpfully in trying to determine if I need a different chain ring.
Nice idea but I guess not really needed, there are a lot other things which are more important.
it would be great to have a post ride statistic showing how many times you have clicked the controller to go to an easier gear when you are already in the easiest gear available and same for the hardest gear. this would be a good tool to use to see if a lower or higher gear ratio is needed than the current setup fitted.