while not modular, NoLimitz is introducing an aftermarket mast. They could conceivably make a universal version and sell adaptors
www.sunsetsailboards.com/products/nolimitz-foil-mastseems like someone could make a universal mast with a standard foot, and then instead of buying custom adaptors, people could just fab custom fuselages. would be nice if there were some standardization.
right now just the idea that you could use SABFoil and Slingshot Phantasm wings and stabilizers on the same fuselages w/ minimal customization is exciting.