Checked with my mfg contacts as promised and here's what I was told.
* The advertised draw bar pull specification is exactly what the definition of draw bar pull is (see below). Draw bar pull can pertain to towing a disabled forklift, towing a trailer, locomotive pulling rail cars, farm tractor pulling a bottom plow etc... as long as you remain within the manufactures draw bar pull specification I don't see the issue. Draw bar specifications for any type of equipment that requires a draw bar pull specification are calculated taking into consideration center of gravity, braking, converter stall, horse power (IC or Electric) etc...

o Drawbar pull is the pulling force, or pulling ability, of a vehicle. The definition of drawbar pull is the towing force of a truck or other industrial vehicle, exerted at its coupler (or equivalent) in the direction of motion of the coupling point. Drawbar pull is typically expressed in pounds or Newton's