When building a boat, a common technique is to build the sides of the boat, flex them around bulkheads and temporary forms, and then attach chine logs along the bottom, after which the bottom of the hull can be attached. Often you can put the chine log along the bottom edge of the sides before you flex them around the frames. You can also attach the gunwale before flexing, and even apply fiberglass to the plywood before flexing. Much simpler to work with flat sheets then to apply when curved.