I would comment that the double cans have the double effect of making lift in NE positions with no need to enlarge the fuselage more.In a mid wing design as this is it makes perfect sense to want to ''keep'' the air in the fuselage at the bottom part as well.You can think of the cans as winglets on a very very.. VERY low aspect ''wing'' ,the fuselage. Having more and more side area especially in the front is not the best solution for F3A as we are flying in cross wind all the time and it drifts our planes. Further more large cans especially two of them act as normal wings making possible to have smaller main wing with a positive effect on rolling and snapping maneuvers ,an ingenious solution by an ingenious man..