Man this ones a long read.

I'm on the side of the fence that had been suggested as being technically defined.

The "Flaperon" mixing function uses two servos to individually control two ailerons, combining the aileron function with the flap function function via a single programmable mix.

End of story for me. I have never seen FLAPERONS defined by variable standards for various types of flying.

As mentioned by others it is often required to effect an additional mix to control pitch changes when "Flaperon" is activated, same goes for actual flap empanages. This is known as Elev-Flap mixing and requires a second mix. This is an entirely different function and mix... Since this is an additional mix and has an additional name or function it only makes sense to me it's not technically a part of FLAPERONS.

I think for the most part 3D guys don't use flaperons/spoilerons and such (maybe I should qualify my assertion Giant Scale 3D guys don't use this function much if at all). In any event its pilot and model dependent.