I realized that I may have been misleading. Double surface wings are very common with hang gliders and by far most paragliders are full double surface. The single surface parafoil paragliders are the rare exceptions for the hike & fly guys where every gram matters more than pure performance.
The kite board kites on water are commonly the single surface inflatable leading edge designs, with the racers and performance guys using double surface parafoils, ram air, with "one way valves" to stay inflated when you crash them, so relaunch is possible. Much higher L/D with the double surface, which fly closer to the edge of the "wind window".
The different kinds of boarders have different needs. The guys on regular surfboards out to ride waves prefer designs that can be "parked" with very little pull so they can focus on the wave while surfing then using the kite to tow them out for another ride & to yank them out of trouble when they get into sketchy spots. The hydrofoil board guys like lots of control of pull, with lower cruise power needs, while the racers on asymmetric boards want max power.
I'm using a 2.2 sq. Meter "trainer" parafoil as exercise gear and sometimes comedy. A chair bound buddy yanked himself out of his chair with mine. How hard it pulls depends on airspeed and you can get the silly thing screaming and drag you across the ground. 80 foot 2x 200 lb. test lines.