I don't think this moves the boat out of reach for the homebuilder. Here's my reasoning:

1) I'm an engineer and can design a working curved foil solution if I feel like dropping the money to make it happen. I'd likely blow up a lot of boards and the performance may be sub par but it can be done.
2) I can just as easily buy a set of curved foils from a major manufacturer and fit them to my boat. Once again this may be sub par as board location and trim are critical. Granted several people in the A-Cat's are doing this with success.

As far as manufacturer support, I think it will happen. Enough big players have experience with the technology that the costs should remain reasonable and even if R&D is pegged at $30K and production of the boat is say 100, $300 per boat is still pretty reasonable for the chance to literally fly around the course.