Thus far, the planks sit pretty flush to the wall and the little space heater keeps them standing. If I don't take the heater, I angle the outside plank slightly so that it leans on the other two and keeps them all in place. One of these days I will place an unobtrusive attachment on the dining benches that will hold them in place but haven't found a pressing need for it yet.
When I travel, the planks are in bed position and I pack on top of them and below them, it gives two levels of storage enroute. (Clothes, fishing poles, food, etc)
2012 FR Flagstaff T12SDTH
1996 Shadowcruiser Pop Up Truck Camper
1967 Newell Motorcoach
2003 Ford F150 5.4 V8 Triton Super Cab
2004 Nissan Titan LE 5.6 V8 4x4 Crew Cab