In my 1970 Venture 21 there is no bulkhead or other support under the cockpit. ie under the winch.
However the weight of the winch is spread between the cockpit seats. The cockpit is support by the transverse back of the cabin. distributing the weigh in the cockpit to he hull.
The Keel weighs about 400 pounds so you are putting about 200 pounds on each seat, or weight of one person.
You can damage the cockpit when on the trailer with a tie down that is so tight that it pulls the boat down on the trailer pushing the boat bottom up against the cockpit.