Wahoo ELEMNT bike computers export standard FIT files. Download from the Wahoo app, import into MetricsOverlay.
Export: Wahoo app → find the ride → export as FIT. You can also sync to Strava or TrainingPeaks and export from there.
ELEMNT records all paired sensor data: power from KICKR or Powrlink pedals, heart rate from TICKR, speed and cadence from standalone sensors.
For indoor KICKR rides, the FIT file has power, cadence, heart rate, and virtual speed. No GPS since you're stationary, but all other overlays work.
Wahoo makes bike computers, not watches. If you wear a Garmin watch with a Wahoo head unit, you'll have two FIT files - use whichever has the data you want.