PF, An interesting concept I learned flying hang gliders is that the angle of attack of a glider wing for maximum lift and slowest descent isn’t the same as the angle of attack for best glide distance (ie. efficiency).
Beyond adjusting the thickness, camber, and aspect ratio of a hydrofoil wing, I imagine adjusting angle of attack of wing/stab ratio with shims can make a foil more or less tuned toward glide vs lift. For wave foiling, I imagine you want high AoA when on wave face but a more efficient AoA when carving and bleeding off the energy you gained from the wave. Unfortunately, we have yet to see a foil that you can change wing/stab AoA relation on the fly. What if we had a foot switch that adjusted stabilizer or wing AoA between “slow-lift” and “fast-glide” settings.
Another variable geometry solution is changing aspect ratio of the wing, such as hang glider VG setting, or the military fighter jets with this ability. Doubt that would be easy to manage on a submersed foil wing, however. Food for thought.