Joe Mac, I read the Torklift specs and engineering intent, and this does seem like a possible solution for sway and body roll or lean control. The device appears well endorsed by users, that's a consideration, including folks who carry a cabover camper.
Apparently, the system offers a transition to the overload leafs plus support during the load and leaning phases that lead up to full overload spring action. OEM main spring stacks are actually "progressively" rated as they approach the overload mode, applying more resistance as the springs flatten. Apparently, Stableload takes this a step further by increasing the main stack spring rate even further when you carry a load and connect the Stableload links. The device applies the overload spring's force to the main stack—earlier in the cycle.
By design, your Chevy or my Dodge Ram 1-ton trucks keep the overload spring some distance from the spring stack. The Torklift helps to take the "gap" out of the overload spring application. This also means that your spring rate would be stiffer than the non-overload leaf stack when the Stableload is linked. Essentially, you'd have a stiffer resistance to the load at all times. This could be useful if you have two tons in the bed and cab!
Two tons in the bed and cab is a lot. If OEMs set up the rear spring main stack rates to handle this kind of load, the ride when empty would be impossibly harsh. Instead, they use an auxiliary overload spring set apart from the rest of the spring stack. This provides reasonable ride quality when empty or loaded—running on the main stack...If you were to leave the Torklift Stableload Quick Disconnect hooked up when unloaded, you would have a harsh and rigid ride.
Note: Maybe an OEM could incorporate an electrically actuated or automatic Stableload type device that would operate like quick disconnect sway bar links on a JK Wrangler Rubicon!
If used correctly, the Stableload Quick Disconnect does sound like it offsets the OEM rear spring set's "on" or "off" use of the overload leaf. When hooked up, you're adding the additional tension of the overload much earlier in the spring rate cycle. The more gradual transition could improve both the spring rate and handling. The stiffer rate would reduce sway and body roll, and the smoothness of the more progressive transition/rate could make vehicle handling more predictable.
Carrying two-tons in the bed and cab is really a hefty load. You must be running at gross vehicle load rating all of the time when the camper is onboard. The Stableload may help handling and spring rate transitions; however, the actual load on rear wheel bearings and tires remains constant—and very high. Something to consider.
Footnote: I recall seeing this Torklift package at the SEMA Show last year. There was discussion around drilling the spring leafs to install one version of the device. The kit includes a special drill bit and guide. This is spring steel if you're considering a home installation. Drilling could take a while...