Under "2 and done", do you restore critical port infrastructure to dunes if they get destroyed by a hurricane twice? Port infrastructure can't exist on its own, it needs a community behind it which needs schools, parks, houses, etc.
This is a problem that the insurance industry will need figure out so they can price risk to the area that's wiped out, the way the home is constructed, etc.
In my mind the debate is how FEMA subsidies will distort the insurance markets. Perhaps they could serve as a "2 and done" re-re-insurance provider?
A great counterpoint to this argument is that an insurance oligopoly might "price gouge" after a big event like Ian, which could kill the community that's needed to support the vital port infrastructure. Ultimately if FEMA subsidies were removed from the picture, shipping costs would increase to price in the risk of hurricanes for the area. Either way we're all paying for it somehow.