Hello
afraid I know nothing about the Bi-Fly (and some will argue I know nothing about aerodynamics when they read this!) but I have always understood that the idea of a greater incidence on the top wing was that, due to the upper wing being forward of the lower one (stagger) the upper wing would stall 1st and bring the nose down. The other way round, as you mention, would by the same theory put the plane into a deeper stall.
Just my thoughts - anyone else?

cheers
Rick