That's a big if Dave and the consequences of a screw up here are, well I'll leave that to your imagination.- flybynight
That's not a big if. It's easily determined by a moisture meter and good surveyor. You eliminate many good cored boats and boat models with a sweeping generalization about not buying a cored boat below the waterline. The only way this can happen is if thru hulls are inserted improperly. Easily tested with a meter.
So I guess you have elimated Najad and Halberg Rasseys two of he finest made boats from your list as both are dynacell cored.
You are making a mountain out of a molehill. Just check to make sure the boat your are buying in particular doesn't have moisture intrusion. Eliminating cored boats just on that basis eliminates many boats or no reason.