I am in the process of customizing a trailer and want to include Murphy style bunk beds mounted horizontally. I have found several plans but I am concerned with how they mount the sleeping surface to the frame. After creating the rectangular frame, the recommended platform is 3/4" plywood attached with pocket screws every 16". I know pocket screws result in strong joints but I just can't see this being strong enough to support a 250# person tossing and turning during the night. Am I being paranoid or rightly concerned? Is this really going to be strong enough to work or should I be looking a some other form of construction? Total weight of the finished trailer is also a concern. TIA.