I just bought and installed one of the GMC trifold hard tonneau covers on my 2020 AT4 Carbon bed. I'm embarrassed to say it took me 2+ hours to install. I think the French version of the instructions was clearer than the English.
I did lose 2 J clamps inside the frame of the bed and I missed a clamp on each side with drill hole, so mine only has 4 bolts each side...
Its heavy and clunky and it will NEVER get taken off, it's just too difficult, so I hope the wife doesn't buy something big to bring home.
Not impressed but it was the only option out there...