Hello, you are correct in that Athletica is not integrated with Training Peaks.
It is integrated with Strava.
I download the workouts from Athletica (Export ZWO), then upload them into Documents/Zwift/ Workouts/ then the longer number. It’s not a quick and easy integration but the workout lives in Zwift Custom Workouts for you to use at any time.
I don’t know about Technogym.
You don’t need TP anymore… simple enough to import zwo files (the key sessions are handful anyways) to Zwift, and then you’ll find them in your Custom workouts inside Zwift. I have them all in my library (Zwift) and I tweak them directly inside Zwift once I have the key sessions in there.
I believe Technogym links with Garmin with Ant+ BT connections so check with your Garmin connect and Technogym how to sync. Or you just follow the instructions from your Garmin watch while running.
I believe we have reached out to Zwift several times about integration. It is up to Zwift I think… hopefully soon!
We also do weekly Zwift rides and Zwift race season, many of us are regular zwifters