As I mentioned in a similar thread, I installed the Ground Control system on my BH3670. As far as rigs go, they don't get much bigger unless it's a TH. I also have the OEM rear electric stabilizer, so that gives me six points of contact. I still put my cribbing pads under all of the feet, just so that I don't have to extend the jacks as far. Helps spread the load, too, since we're on not on a paved site.
At the time I did it, Reico-Titan was still and independent entity and not a subsidiary of Lippert. And the cost ($2500, delivered) was way too attractive to want to haul the rig to Elkhart for the Level-Up install.