Ability to upload externally generated structured workout files.
It would be very convenient to have the ability to upload a structured workout file into TrainingPeaks. I prefer to build my workouts with my own tool and export them in the format I desire (like TrainerRoad .mrc format or Zwift .zwo format). Being able to upload them to TrainingPeaks will help me keep track of the different workouts I've created. I don't think this would be a difficult task to implement since the common workout file formats have standard syntax that is easily parsed. And TrainingPeaks already provides the option to download workouts as these different file formats so going the opposite way shouldn't be a problem.