Have to agree with tj that, despite the homespun appearance of his wooden "sawhorse"
rig, it seems to have adequate support and provides clearance for trailer removal. The beam does have some visual deflection but won't fail.
Don't know if 48Dodge actually calculated the loads and spans with his design, but I would have engineered the beams at bow and stern, for point-loading and perhaps used plywood gussets in place of the diagonal braces to resist racking.