What makes you think "heavy seas" are going to incline the hull if a jeep in calm water fails to.
Maybe read up or watch a video on inclining test.
Whether you have no weight added regarding hull incline produced from a Jeep or from any superstructure at all... in other words employing a strictly bare hull... the heavy beam wave would by its lonesome incline the hull. Whereas calm water would not. Therefore transverse stability in regard to calm water affecting boat hull heel in comparison to heavy beam sea affecting boat hull heel is like comparing apples to oranges.