Well, no matter how it looks, fiberglass hulls don't "spread". They might become concave, or indent, according to how the stands were placed, but the actual plastic will never 'spread' out because of the force against them.
If there is a case of the hull becoming separated from the bulkheads, that's a differnent story, and also not due to "hull spread".
Wish mine would spread a bit more. Door frame to my aft cabin door has compressed and I can't get the door to close. At least in my situation if it stays that way I can trim the door a little to make it fit. Tricky to stretch a door to make it wider.
The water is always bluer on the other side of the ocean.