As far as I know Kelsall and I are the only multihull designers who are actively pushing the envelope on rapid hull construction. I have commended him for working the problem so actively. And I have criticized him in the past for ignoring global loads (he did then revise his half length panel method) and for advocating polyester resin. He does seem to mistrust materials testing and composite engineering, which is fine.
His claims of 5 hours to build a full length bagging table and KSS being “perfect, with no downsides” made me very skeptical. Especially after KSS keeps changing. Evolution is good. I do expect him to discover CM in composites soon and declare he invented it.
I have heard about KSS panels splitting open during fold-up but I was interested and surprised when I got this firsthand note from Don while I was overseas. With permission…

“I hosted his first workshop on the East Coast of the US, about 10 years ago. I can tell you it took me longer than 5 hours to build the 32′ mold table, with a continuous sheet formica 32′, without any joints. Derek arrived with 2 sheets of paper one was a sketch of the 30′ cat and the second sheet was metric offsets. I spent a week with the man 12 to 16 hours a day and I can say he held all information close to-the-vest. I spent $7,000.00 on materials. We had 12 persons at the workshop, he charged $350 or $400 per person. I provided 3 meals a day for everyone. Derek walked away with $2,800.00. I did charge him the cost of the bulk food. We ended up with 4 panels, one for each side of the 2 hulls. After all that he never provided any additional plans and I dropped the project. The table did provide very flat panels. We had trouble with the gel coat. There were sections that looked like wood with worm channels. I had a large barn that was built in 1860, the boards on the side walls, had gaps that were a 1/4″ to 1/2″ between boards. It was summer time in Pennsylvania but it would cool off by 10:00 PM. The gel coat was applied at nite. That, cool air coming through the cracks, may have caused the gel coat problem, the mold table was 3′ to 4′ from the wall. None of the 12 persons purchased plans from Derek.”