I haven’t seen that “double deck” method yet Simon but it sounds like a clever way to load lightweight pallets that have double stacking restrictions on them.
Our Krone Euroliners are a nice trailer but a lot of cross members were cracked off the chassis rails with only the floor holding them in place at about 5-7 year mark on two different batches.
The boss reckons most likely caused by the all welded construction not being flexible enough to twist when on boat ramps or entering sloped ramps to loading bays and so on and maybe even bad roads.
The next purchase will be a bolted construction he says like Schmitz have.
To add to original posters question, if the back row is staggered, I put the cross ties at the last full row and then pop a strap or two on the the single left over pallet. There may well be better ways.