If you're boondocking, you'll probably want to carry extra H2O in the van. Maybe a portapotty. If you're van is set up similar to a Sportsmobile, your probably already set up and ready.
Of course the usual AS power improvements, ie upgrade to 3 stage converter/charger so you don't kill batteries. Convert any incandescent lights to LED. Dual 6v AGM batteries. Maybe portable solar so you can have it usable on either the van, or the AS. An extra battery in the van with isolator to run the Engel. Tire chocks/blocks. Shovel. Spare tools. Jack with plywood base that will work on AS to change tires. Lug wrench to fit AS. Tire plug kit, portable 12v
compressor. Sand ladders. 50 amp adapter. Water hose. Volt/ohm meter.
Oh and a winning lottery ticket😄
Then relax and enjoy life.