John is right about the footwear rule- I don't think anyone in the U.S.
will be tightly enforcing it. We may see a Team Trials organizer
saying "If you plan on racing internationally, you are expected to
follow all rules for international racing, including airbag and bootie
rules." But I don't think anyone will get disqualified (probably).

By the way, those with big feet should think about ways to reduce foot
size. Smaller feet make you a faster C-1 paddler.