Yeah, I do not trust those plastic supports. I did notice that they were not screw in but stapled. This is a design flaw because it allowed them to buckle. Also only 3 of the 4 pegs were making contact on the shelf.
2015 F350 4wd 6.7 Powerstroke, Firestone Airride
CM custom hauler bed
2016 Northpoint 377RLBH