If you figure MAC for the normal bi-plane and both wings the same size and CL 25% of MAC, it is 75% of MAC of the forward wing. But considering that the total of both wings has 15% more lift than normal monoplane wing of same area then forward wing has 30% more lift than the rear wing if both are the same size? So adjusting the CL to compensate for the difference in lift must be quite an interesting equation?

And angle of incidence, that is just a big question mark.