The ArduPlane 3.3 version in APM 2.5, includes the FrSky telemetry protocol through smartPort?
That was added in Plane 3.1.0
In which version of ArduCopter was the interface for FrSky SmartPort included in the APM?
It wasn’t in the last supported firmware for APM. However, there are external conversion solutions. I used a Teensy for this purpose.