Just as a matter of interest, we've got the lashing down thing well sorted now....
We spent literally days working out how to lash bikes down for a potentially frisky Bay-Of-Biscay crossing and a couple of thousand miles trip on land- we really didn't want to ratchet anything down on the suspension because a customer finding a blown fork seal on arrival in Marrakesh would have been a bad thing to put it mildly, but to get the bikes secure enough, you can't go off either the centre or side stands.
We used a combination of fork bracing (blocks with cross bracing inserted under the fork stanchions and onto the tyres) and 8 inch square section fence posting with foot long pieces of inch thick pine plank to bridge the frames/sump guards....we set these up indvidually for each bike allowing aboutan inch and a half of suspension travel before tey puled solidly down on the blocks.....then a pairof ratchet traps front and a pair rear lock the bike solid to the deck of the trailer.
Not one bike moved an inch on ether the way out or the rough return journey- we did incorporate some high tech padding solutions (AKA the sofa cushions from Dani's old three piece suite ) in strategic places to make sure there couldn't be any rubbing of bikes whatsoever, but it all worked very well and we didn't even disturb the Moroccan red mud on Mutter's ADV on the way home