2020 Sierra AT4, 5.3L
275/60R20 Mickey Thompson Baja Boss AT
20x9 Fuel Rogue +1 offset, Gloss Black w/ Machined DDT face
1.75” ReadyLIFT Leveling Kit with UCAs
If you look up this 22 x 9 factory GMC wheel (Part No. : 84799392) at http://accessories.gmc.com/ , the offset is listed at +1.1" or +28mm. If I remember right you need at least 4.75" or 5" of backspacing to clear the caliper.
Tailgate release work just fine from inside the truck with the Truxedo brand tonneaus. I have the Truxedo X15 Pro cover on my 2020 AT4, and have released it numerous times for the cab.