>> do I have to ride inside the Wahoo app for 10 minutes…
The warm-up doesn’t really have to be within a particular app. You could ride for 10 minutes with no app running and then launch an app to do the calibration. The 10 minutes is just to get things warmed up.
You could try the calibration within Zwift if you have the wrench icon on the pairing screen next to the Power Source. You could ride in Zwift for 10 minutes, then calibrate through the pairing screen, then continue riding. Some people ride for 10 minutes in Zwift, but then unpair the trainer from Zwift, jump over to the Wahoo Fitness app [or Rouvy, for example, for Cycleops trainers] to do a calibration, then back to Zwift to repair the trainer and continue riding.