I spoke to both Kauli and Keith about how the first twin fin board came about and I think you have to give Kauli a lot of credit for driving this and on one hand having a clear idea about where he want his shapes to go but on the other hand also being open to taking big steps in promising but kind of unchartered terrain. But of course Keith was instrumental in realizing the ideas. It took only a few tries to get something that worked rather well. I think that for Keith and Quatro, most of the time put in has been to make the twin fin boards work for others than Kauli, but other top sailors and more recreational sailors and I think Keith is a master in getting good sailors to use his board and then use the feedback he get to learn and to improve the shapes.
But saying that Quatro twin fins are the only one that works is taking this to far. I would say they are kind of special shapes with a special feel to them that feed through both on their faster rockered boards and on their extreme boards. There are many other totally differerent approaches that work just as well, only with a different ground feel.