on the Pixracer the Wifi board is located pretty close to other components - especially one small drones the Pixracer was desiged for. To reduce any problematic interfence it should be switched off during flight.
Anyway Wifi is nice for shortrange telemetry and log download. But for long range telemetry other radios are required. Hence, I suggest to implemet some switch to turn it off before take off. This might be arming, or maybe even better, after pushing the savety switch.