Great points. I recommend you to get in touch with the TrainAsOne founder. The HealthFit is just a way to sync between the Apple native workout app and TrainAsOne. Other apps can sync directly. Good luck with your challenge!

PS: The Workout app by Apple did get great updates in the recent version of WatchOS which are super for the amateur runner / endurance athlete. I'll write an update about that soon... 🤞Apple will allow easier syncing via the Workout app as it will benefit all for sure.