Just announced recently: enhanced import/export of workouts between Zwift and Intervals.icu.
Raises an interesting question re: Systm. I know my TrainerRoad workouts export automatically to Intervals, so conceivably could then port from intervals to Zwift? Anyone using Systm and intervals together where your workouts are ported to intervals?
Yes, I have my (SYSTM) Wahoo account connected directly to Intervals, and previously Zwift connected indirectly to Intervals by being connected to Wahoo:
If anyone is using Wahoo as a go-between from Zwift to intervals.icu, there currently seems to be a bug with Wahoo correctly syncing third-party workouts to intervals:
David (intervals.icu creator) has logged a support ticket with Wahoo.
You might also just want to sync Zwift directly instead of via Wahoo.