My understanding of the "wings" rule is that it allows sailors who for example sail a narrow platform boat (think Mosquito, beam 2.2m) to add wings to the max of 300mm each side, giving equal RM to a fully-optimised boat. From what I understand they don`t have to be folding, if they`re fixed, the platform is still only measured with one rack.
The only advantage I can think of with this setup is that such a boat will fly a hull in less wind than a wider platform, while still having the max. RM of a full F16 design. So light wind performance might be slightly better (you can fly a hull earlier), but with the weight of the racks, do you really gain anything ? Seems self-correcting, which I`ve found most of the well-considered rules to be.