No, this is not what I meant. You are right, Apple Health does not route power data.
I meant the automatic link between Garmin Connect -> Stryd Powercenter (see here
https://support.stryd.com/hc/en-us/articles/360001001353-Link-Garmin-Connect-with-Stryd-PowerCenter).
So the process would be to export the file from WOD to RunGap (e.g. via share sheet). From there, synchronize to Garmin Connect. And the automatic link will distribute to Stryd Powercenter.
As Garmin changed several times their policy if they push 3rd party workouts (workouts not recorded with Garmin devices) via their linked platforms, I am not sure if this approach will still work or if, if it will work in the future also.
Hope this clears it up.
Unfortunately, as you correctly pointed out, Stryd Powercenter is not an open platform when it comes to uploading workouts non-manually from other apps.
Edit: there might be ways to do the same approach with other training platforms (e.g. from Polar, Coros or Suunto) but I am not familiar with these.