This might be okay when the helicopter is pitching upward, (ie the torque of the blades tries to twist the helicopter upwards and sideways on maximum pitch) but on a 3d heli, once you invert it and go the other way the tail angle might work against you. I am only guessing here thought....

 

Probably 3 axis gyro can deal easily with such setup even in 3D flight.

I guess.

 

Interesting read here. I currently have the tail on my 120sr tilted slightly "down-angle" by accident on install of new tail boom assembly. I have not noticed anything unusual, but then again if there were anything "off" I probably re-trimmed and simply ignored it. After reading all of this, I'll have to pay closer attention to tail reactions just to satisfy my own curiosity.