I'm sure Agile has tested them and they work well. That said, there is likely a reason why Magna bolted the factory Grenadier sliders to the frame. When you drop the car on a rock the weight of the vehicle is then suspended by the body mounts. Those mounts are engineered for compression forces not tension forces. Again, I'm sure Agile has tested them plenty and they do build great stuff.The Agile sliders are unique in that they mount to the body, but in my experience with other vehicles this is a non issue. The vast majority of sliders for the Jeep Wrangler are body mounted and they are more than up to the task. Even the OEM sliders on the Wrangler Rubicon are body mounted. And unless I am mistaken the AO sliders can be removed and the vehicle returned 100% back to stock with no visible alterations.
Both Wranglers and Broncos have factory body mounted sliders but Ford and Jeep engineered for those body mounted sliders when they designed the vehicles and Magna did not. Jeep and Bronco owners who intend to use sliders typically upgrade to a frame mounted slider.