For those who have moved over to Zwift or were already using it,
Announced on the Zwift forum:
Completed Zwift activities can now upload to Wahoo after you setup the connection. This is just for completed activities, there’s no support for SYSTM workouts appearing in Zwift so you can do them.
If they get SYSTM workouts to push to Zwift, I’ll sign back up with SYSTM. I ended up choosing Xert for the season, but whoever can push to Zwift is the winner and I’ll switch back. It seems like such a simple thing, but no idea. TrainingPeaks can do it.
This is a good thing. Not having to separately record the ride to have it tracked in SYSTM will probably get me using Zwift more often, even if it isn’t exactly my cup of tea.
It will be interesting to see what info they send over. Zwift .fit files seem to be missing lots of info that SYSTM .fit files include, like sensor identifiers, and the file from a ride that I checked out had some incorrect info in the session field, like zero descent and maybe one other that didn’t affect the quantities I care about. RGT and FulGaz also don’t include sensor info, and SYSTM didn’t until perhaps early 2022.
Hope someday theres a way of getting system workouts in zwift or any orher similar app like RGT was able to do because i dont really like to repeat videos. I dont mind doing the same workout several times but do need a diferent scenario/visual motivation and picking a systm plan where most part of the wo were already done is not very motivational for me.
For Zwift platforms that allow you to provide your own ZWO file, it’s already possible:
It’s not an out of the box tightly integrated experience but there are people already riding SYSTM workouts on Zwift.
Time consuming 
I tryed to convert fit files from system wo to the zwift wo accepted formats and they do convert but uploading to Zwift always gives a error message.
If you can, just run SYSTM and Zwift at the same time. Set up SYSTM to control the trainer and Zwift should not be set up to control and then you can easily do the workouts in Zwift. All you need is a trainer that is dual Bluetooth or ANT+.
I’ve done dual runs before, but I actually like Zwift’s workout layout. As simple as it is, I like seeing the colored gates in the distance and working towards them.
My kikr core does BT and Ant+. I’ve tryed that before with RGT and Systm and it didnt work. Ill try again with Zwift but if it works wont I have 2 exactly the same workouts uploaded to strava and bow to system calendar? If so i’ll have to delete one in each place 
Also the workout creator is not difficult to use. Ina couple of minutes you can create a workout just need to know in advance the time and watts you want for each part of the wo.
If you have BT and Ant+ and I will assume it’s one computer. Set up Systm exactly like you normally would (with either BT or Ant+). Once that is set up, open Zwift and set that on the paired devices screen (using whichever BT/ANT+ you didn’t use before) EXCEPT make sure that the controllable is NOT highlighted/selected. That way Systm controls the resistance on the trainer (not Zwift) and Zwift can read the proper power and move the avatar.
Here’s an article from 2020 from Zwift Insider on how to connect Trainer Road but it works the same way with Systm - Running Zwift and TrainerRoad Together | Zwift Insider
Got that and will see if it works.
And what do you do with both workouts beeing uploaded to STRAVA and Systm calendar? Delete one? Wich one?
If the starting time stamp is the same, the one that’s uploaded first will show up, the second won’t. It’s a Strava thing. When I do a dual recording, I sync the Systm workout first, the Zwift workout then doesn’t come through.
That’s never been the case with me. They both always seem to upload. I usually delete the SYSTM one because the Zwift has at least fake gps, distance, elevation. But I will rename it with the name of the SYSTM workout in case I’m searching for it later.