I have done that, it works fine.
Actually, in principle, S.Bus socket also could be used for telemetry (Tx pin is not in use). I do not think that either one of these variants is hard to implement (GPS - telemetry, or S.Bus - telemetry). Question for developers?
BTW. Sparky.2 does not have these limitations, it has separate I2C port.
P.S. What kind of video system are you using for over 2 miles flight distance?