I returned the cargo divider. The problem was not with the brackets (which i had figured out i could mount upside down, which is neat), it's with the piece that slides inside the rail, with a protruding bolt that the brackets screw onto. These would not slide past the tonneau
's bolt heads which were 2mm taller then the stock rail bolts. I could have slid them in, then added the bolts, but this would have precluded repositioning the cargo divider outside of the region between the bolts. I'm looking to fashioning my own system using the cleats, a cargo bar, and a tailgate webbing thing i found at a garage sale.
In addition to the carrier problem, i had these other two non-tonneau related gripes
1) the brackets are huge, making them a shin hazard even after removing the divider itself, 2) they dont slide smoothly in the rails, making shifting it to the front to accommodate dogs unwieldy.
Those two things made me less inclined to 'solve' the problem.
Thanks for all the help though.