Yes I know and they backed off from the super thin sections they once used and went to a little thicker section.
Still, iirc, Smith said "fat foils" can work.
If we're talking about the future, it seems to me the current models must fail. Trying to attach a high efficiency foil to a contemporary hull design is futile; it puts the cart before the horse. The hull must be redesigned with the foiling considerations first. Look at sail rocket, look at Smith's drawings.
http://www.geocities.com/aerohydro/designframeset.htmhttp://www.wired.com/autopia/2013/01/ff-paul-larsen-sailrocket/all/
