If you have ever followed a 5th wheel on a typical road - bumps and cracks - you will see how much it twists. I'd want more than one point of attachment to my trailer. as the rack will twist even more. Just what I would do. It may work perfectly for you.
Elliott, Vicky, and Sadie, our GSD
2014 Redwood36RE Titan Disc brakes, 17.5 " Sailun Tires
2013 RAM dually, CTD, Aisin Tranny, CC, LB 4x4