Hmm.

I scratch-built a 14" extra 300, but I never could get it to fly very well. It was WAY to touchy on ailerons, even with LOTS of expo. The other problem I had was that it was so fast. It really zipped along like a rocket.

Seeing as how that mini Tensor also experienced the rapid speed, I dont think you could build one that small and get it to slow down.

The problem is the weight vs wing area. They dont make the avionics light enough for a plane that size, and if you use the current lightweight componants, it has to fly fast to stay up due to the small wing area. You could shape the wing into an airfoil shape for more lift, but then you would lose some of the 3D capabilities. The only exception I found to this so far is the IFO/UFO type airplanes. Their flying wing type design gives enough lift in a small package to pull it off.