David:
And do you not fear for this connection when you have 380 pounds of crew weight sitting on the same hull when it lifts out of the water?

I would suspect that a connection that can handle hull flying will be capable of "flying" crewless while being trailered.

After reading how others have done it I ended up with the attached. The beams slide well along the "plastic" lumber and the dolphin striker drops into notches at the front. This takes care of any fore/aft movement. When the rear mast support is unpinned and removed, the rear of the frame lowers to the ground. This reduces the amount the boat needs to be lifted to get it onto the trailer.
In these photo's the boat was loaded onto the trailer for the 300 yard trip from the sail club to my cottage.