[Plumper]

Is the weight of the boat on its keel or is the weight on the jack? The keel should be carrying the weight and the jack should be balancing the boat. Lighter built hulls that oil can when on jacks should have the jacks placed on areas that are supported inside with frames or bulkheads.
Properly designed and built boats should not oilcan on jacks. Particularly small boats.
I would be concerned and ask my surveyor. I would not like to see that portion of the hull flexing when beating into a nasty sea.