There’s also Flying Wings (https://en.wikipedia.org/wiki/Flying_wing),
but you need a special foil section for it to allow to be “flyable” or statically stable.
Since with aircrafts you set your CG once and control the plane via control surfaces, it’s hard to compare to the weight shifted control we do on our foils.
I personally don’t think a Flying Wing would be a good setup for a foil unless you have control surfaces (ailerons) and a processor/controller that helps you keep the foil level (which would be kind of an autopilot, or controller like they’re used in drones)
As for the Audi Foil, I’m not really convinced of the setup. The backward bend mast is just a design thing I suppose, and the tiny tail looks really small.
I’ve seen that thing in Kiel last year, I was there when they did a promotion run during “Kieler Woche”. Not sure how long they’ve been in the water, but it didn’t look to “smooth” and only starts foiling at quite high speeds I believe (i don’t have any data, just from seeing it)