Folks,
The prototyes -- and all of the R&D boys -- birds are all as follows:

engine +1
wing 0
stab +1

and all fly beautifully as far as thrust angles.


We are actively researching why some customers' production birds have such varied thrust angles.

The model DOES have a pitch to the belly in knife edge -- as do most aerobats -- which requires mixing to resolve. Yes, design changes could have been made to resolve this, but such changes affect other flight parameters which were given priority. Using the proper CG has a huge effect in minimizing such a pitch.