Well, the online the brochure for the EXB-060 CUT model Ag-Krane shows, I think, a JD large frame CUT of some kind lifting a round bail over a fence for feeding. The specks for the EXB-060 are listed as "1200 lbs to 11-13' with lift arm extended", "2200 lbs to 9-11' with lift arm retracted", and "1500 lbs to 8-10' with forks". There is also a note stating "not for use with tractors weighing less than 2500 lbs."
I've only seen the Ag-Krane on the dealer lot, not in action, so I can't vouch for how well it does or does not work.
However, the also make Ag-Krane's designed for 100-300+ HP tractors (MSL 096 HD). In other words large Ag tractors, probably weighing in at 12,000+ lbs. There are pictures of this model (MSL no less!) lifting two big round bails at the same time and stacking what look like 4x4 big square bales to 4 tiers high.
Just for completeness, they also have the MSL 072LT model Ag-Krane designed for 40-120 HP Ag utility class tractors and the MSL 072 model designed for 70-150 HP tractors.