Wave owners can join and race in both associations, and the differences are minor enough and the boat is simple enough that going back and forth between the two is likely as simple as swapping a sail. I see only winners.
Anyone can sail in both classes with a stock (Hobie) sail. If that makes them uncompetitive at IWCA events, SMOD advocates would say that proves the point that SMOD is the way to an even playing field.
Mike