I am a Chris White fan but this is 100% consistent with my experience. The theory ain’t the reality AFAIK.
No need to weathercock when sailing. They aren’t that big. At the dock, they spin easily if you take off the tension.With the greatest respect to the designer, I sailed next to a mastfoil cat several times. It is a gorgeous boat and maybe the operators didn't know how to maximize the system but it was painfully slow. I'm sure in steady 20+ kt. wind it would be a different story but in lighter air it just wasn't happening. In a really bad blow I might be worried about the masts too. If they failed to weathercock that could be a real problem, they are big!