From order guide:
2022 GMC 2500
X31
X31 Off-Road Package, includes (JHD) Hill Descent Control, (NZZ) skid plates, Off-Road suspension, Twin-tube Rancho shocks and X31 hard badge
1 - Requires 4WD model and AT tires. Includes (QXT) LT265/70R17E all-terrain, blackwall tires. Not available with (ZW9) pickup bed delete.
2 - Requires 4WD model and AT tires. Includes (QXT) LT265/70R17E all-terrain, blackwall tires. Included with (RFX) X31 Off-Road and Protection Package. Not available with (ZW9) pickup bed delete.
3 - Requires 4WD model and AT tires. Included with (RFX) X31 Off-Road and Protection Package. Not available with (ZW9) pickup bed delete.
1 = base sierra
2 = SLE
3 = SLT
X31 Off-Road Package, includes (JHD) Hill Descent Control, (NZZ) skid plates, Off-Road suspension and Twin-tube Rancho shocks
Standard on AT4 and Denali
You'll have to decide if it's worth it -- to you.
Additional info:
JHD
Hill Descent Control
1 - Included and only available with (X31) X31 Off-Road Suspension Package.
1= Base/SLE/SLT
Std on AT4 and Denali (since X31 is standard on those trims)
No RPO listed but
Suspension, Off-Road, includes twin-tube shocks
1 - Included and only available with (X31) X31 Off-Road Package.
Same trim info as the others
Can be ordered on it's own if desired
NZZ
Skid Plates, protect the oil pan, front axle and transfer case
1 - Included with (X31) X31 Off-Road Package or (VYU) Snow Plow Prep/Camper Package.
Same trim info for note 1