Sorry, but I just don't get it... Islands are NOT designed as surfing machines, due to a combination of centre of sail effort, rudder size, weight distribution, hull buoyancy, lack of planing surfaces etc.
Also, did you have the daggerboard down? If so, this is a major no-no, as learned by yacht designers, Whiting, Holland etc when development peaked in the half-ton racing classes, as the hull can trip over the daggerboard.
While the brace bolt is arguably too weak, Hobie clearly chose the current strength to ensure it broke before anything else. The hull has never been in danger, but the brace itself and then the aka is next in line if the bolt is too strong to break. Hobie's solution means that in normal use, swapping in a new bolt gets things back to normal without repairs needed.
I guess you are qualified to carry out these extreme tests though, as you mentioned elsewhere that you have previously sent a yacht to the bottom...
You dont get it, this is the most fun you can have in and Adventure Island ever and whilst they might not be purposely built to surf, it sure is fun getting a long ride.
And yes that plastic bolt that stops everything from breaking is very weak so out they come and stainless bolts go in and if that breaks then I was obviously having way too much fun.
It's not about the design and the purpose, and dagger boards and all that, it's about what you can really do on these things and how much fun you can have. You might die tomorrow and missed out on an exhilarating ride.