I did a bunch of research on them lately. If you buy one, it needs to be for a cab chassis application since our frames are 34” out to out. I spoke to a lady at a CM dealer about a CM AL RS and she had just finished putting one on her square. She seemed to know exactly what to ask CM to do to make it fit our trucks well.
The reason I didn’t follow through is that it limits upward wheel travel if it’s traditionally mounted to the frame rails. Since I wanted to put a camper on the bed and take it through some more difficult off-road stuff, I’d be using a three or four point mounting system that pivots. At that point you have to build a complete subframe, so it’d make more sense just to mount the camper to the subframe.
Long story short, CM can build one to a square’s spec. However, it won’t clear big tires with lots of suspension travel if mounted directly to the frame.