there used to be 2 divisions of 18 squares.
maybe c cats could do that. the soft version w/ a spi. may actually get around the course sooner in some conditions.
when we sailed against wild turkey, the scaled down c cat, winged 18square it was incredible to see it destroy the tornadoes to windward, but it wasn't performing that well downwind.

the reason i said 3 man is because the H21 was a 3 man class. there would be plenty of room for 3, and strong winds would certainly warrant a 3rd person on the trapeze. also i think 3 people could reright the boat in a good breeze.
overall there aren't enough cat sailors in the world, so another type of cat will just dillute the existing classes. there are fewer people with money for cats now that the middle class is disappearing.
on another note, foils are promising, but so are these kites that the guys are using these days. there have been tests showing the kite (no mast) made a prindle19 point better than one w/ a stock rig.