I had originally used commercial carpet to cover the trailer bunks, but I noticed that it was retaining moisture and leaving dark smudges on the paint. So I ripped off all of that carpet and recovered all the bunks and braces with actual bunk carpet. That seemed to work much better!
With the hulls loaded in the arms and the beams lashed to the hulls, I could mark and drill the holes to pin the arms in the correct positions for assembly/disassembly. And with the beams removed and the arms slid inwards I drilled holes for the pins in the travel position. I secured the pins with velcro strips. And added chains to prevent pulling the inner arms all the way out of the trailer when sliding the hulls out for assembly.