the issue with a biplane having two wings close together is interesting.... From a "Lift - to - drag" point of view... having the wings far apart
has merit.... as this isn't a sailplane, a small drag penalty is prolly not too much of a concern.... one could also think of this as a plane
that has an effective wing area less than the physical wing area....

Other than spins and snaps, our AOA's are generally not excessively high.. so the interaction between the wings would prolly be
pretty small anyway...

One might think in these terms... when a wing makes lift, there is low pressure on the upper surface and high pressure on the lower surface.... so when two bipe wings are close.. the high pressure on the lower side of the top wing affects the low pressure on the top of the lower wing.... it is affected... but prolly the sky isn't going to fall and the plane will fly fantastic...

this might be a means to aerodynamically synthesize a higher wing loading during high AOA maneuvers........hmmm....