In one of the episodes at the end of 2018 (at least I believe it was back then) guys were mentioning how nice it would be to have access to shifting/gearing data. The fact is that Garmin (and I think Wahoo as well) are recording these data into fit file. You can upload the file do di2stats.com and see details there… It would be way better to have this included directly in the TR, TP or Strava tho… Being able to see how/what I did on certain segments (gearing, cadence, power, speed) could be helpful in very detailed analysis if needed…
I have only now realised that I kind of forgot to say that it obviously only applies to Di2 (electronic) shifting.
Might be more relevant as Sram AXS starts being used as well.
FWIW eTap data from a .fit file can be analysed by the di2stats site too