I bought a 300# rated 2' high fiberglass step ladder. I can walk it around the truck as needed to get at everywhere on the roof rack, and it is small enough folded to fit in the back or on the rack with gear. I do have one of those aluminum door jamb steps and it seems to hold my weight fine, but the small footprint is hard on my arthritic feet. The ladder went on 3 camping trips last year and works like a champ.
https://www.amazon.com/Louisville-FS...s%2C195&sr=8-5