We do can do 1250 kg too...but not really viable as you can't go far or high with no fuel. ...1500 kg would take big wind and low density altitude, and.....
I guess if you are moving water where you can get a run at, it or non fragile loads it's ok...but trying to vertical out of a 50 meter hole on the side of a mountain or build a tower/drill....better use 1250 kg as your target max.
Not to mention....
6172 lb max external
3000 lb aircraft - never seen one below 2970
150 lbs (15%!!) fuel !?!
200 lb pilot
= 2800 lb (1272 kg) load!!
Must be one of those pilotless drones!!