Okay, I did it. I replaced my "in the way" posts with shelf brackets from Lowe's. I decided to try Velcro Industrial tape to hold the brackets on. So far this seems to have worked, although I plan to take some posts with us on the next trip "just in case".
I have three brackets on each side. The wood is also attached to the
fiberglass notch with velcro, which will also help keep it in its upright and stowed position.