I've noticed that when my Hatteras is on the hard, even blocked properly according to the graving diagram, the various doors inside the boat don't open and close exactly right, etc. It takes a day or two in the water in the spring for her to get her normal shape back.
As far as adding granite countertops etc, I think these boats weigh enough as is. On the one hand, when you're talking about a boat that weighs sixty or seventy thousand pounds, a few hundred more might not make much difference. But why do it? And when you think of something of that weight getting loose in a storm, the hazards, as said, are pretty unpleasant to contemplate.