Twas expedient, lighter, and more economical to make a rail vs decking the whole chassis. Wasn't going to buy a fancy-schmancy motorcycle wheel chock but when they knocked it down to half off I said what the hey:
One man loading/unloading:
D'Oh! NOT aero! I considered attaching the 2x6s
under the trailer chassis for a nice lowering of the bike (might have been cg benefits too) but decided against adding any additional loading/unloading drama caused by having to drive up and down crossmembers... also considered flopping axle/spring assy. so that the axle rides above the springs rather than below... might investigate that further... but then I'd need a hitch insert with less rise.
It's highly likely I'll remove the motorcycle's windshield for the trek.