I hot-melt-glued a flap servo into the wing last night, made up a HD M3 linkage, and played with some geometry.
It works! I need to make sure the flap side of the linkage is properly reinforced (I will wrap it in carbon), but essentially it works fine. The servo will need some work done on it's travel volume, but that should be a doddle on OpenTX with my new Horus.
Now on to the aileron connection...if only I could find my left aileron!