I don't think there is any customization or training plan development. They have their classes and you pick for yourself. There are some canned programs however. Example would be intro to PZ training - 4 week schedule of specific classes. I've not checked out any of the others except the very basic intro to Peloton and that was maybe 3-5 rides?how extensive are the Peloton training plans? Thinking specifically for sprint and Olympic triathlon and if they lay out the whole plan and workouts for you and let you pick high, medium, or low volume like TrainerRoad?
For Power Zone there's a separate app/website and a FB group that curates/develops plans and challenges, I'd think that would be the model. Something like a Strava Summit (or whatever premium is called now) training plan that you then execute on the gear by picking the closest workouts to the plan.