Unless Hosts reccomendation is different than AF, we use ours extensively off the truck with nothing supporting the floor. Lower it down until the jacks are only extended about a foot and it's rock solid for sway.
To spread the load if you want to support the floor, plywood squares under the jack stands or saw horses will work great. I've never packed stuff along to set the camper floor on, don't even do that in storage anymore, but the make your own saw horse brackets and some pre cut 2x4s for the beams and legs would be pretty compact to haul with you.
You'll still want most of the weight on the camper jacks anyway. Much wider foot print than the floor.
