we ran a borg warner product in the race truck years back and the coils gained heat altering the engagement parameters to the point of pissing the driver off. I put a PWM driver on the coils and the current was reduced and the clutch life was no change in wear. ( I attribute the clutch wear ) to the timing of the limit switches. the BW engineers lacked common sense.. the driver lacked patience. and the electrician ignored both and made the ball ramps last and tolerate the 8-900HP
Pine Stump. most yamaha snow mobile heated handle grips will be a cheap source of Pulse WIdth modulated drivers. if you want to play with current control.