A PUP "roof" won't hold a rack. PUP "roof" racks mount to the sides of the roof structure and span the entire roof.
From experience installing solar on my roof, my HW277 roof is tissue paper thin.
~ Fiberglass laminate about 1/16 inch;
~ "Plywood" (a generous description) about 1/8" at most;
~ Air (about 1" or less) "filled" with a frame made of something a bit larger than toothpicks...probably 3/4" x 3/4" parting stop - it could be larger but not much;
~ More "plywood";
~ Interior ceiling material...could be fiberglass laminate or a sturdy vinyl.
Together, this structure resembles the wing of a balsa-wood model airplane.
The sides of the roof are particle board, but in what amounts to a monocoque structure, they can carry a vertical load from a roof rack.
Gutter-mount racks (e-Trailer) can screw straight down into the side wall.
Some have long rails that mount to the side walls and allow the rack to move fore and aft. I've also seen racks that actually attach to the side of the roof. In that case, use bolts to mount the rack, because particle board doesn't hold a screw worth a damn. Stainless bolts won't rust.
I carried my canoe on the roof of my pickup using strap-on roof racks
. Worked well. The canoe required ropes to the front and rear bumpers to hold it firmly, but the racks worked like a charm.
One more reason to move the boat to the TV. Your rig has a limited GVWR. Between the racks and the boat, you consume about 100# or more of that load capacity. I know your 296 has two axles, so that may be less of a concern. My single axle 277 can only carry about 700# of payload, water and so on before it's overloaded.