My SRW 2020 Chevy 3500 4X4 does not sway much at all, even with a Host Cascade. 19.5 tires and wheels, Stable Loads on the main springs and overloads, airbags, and a Roadmaster 1 1/4" rear swaybar. It all works together.
The huge swaybar also benefits me when driving the truck empty, keeping both rear tires planted and eliminating the annoying stock axle hop which occurred almost every I pulled out from a corner, or went up a corner around a curve.
Not the first time around the block. Before we went to a class A for several years, I had a Dodge 1-ton Cummins with similar suspension carrying an Arctic Fox 990 (still in my sig pictures!). But this aftermarket suspension package does add up! For most people I'd say just get the dually.