I also own a Mitsu and found the pump flow to be rather pathetic for FEL action.
My parts manual showed a front crankshaft coupling to drive a lawnmower or whatever via V belts and used an electric clutch.
I purchased the pulley adaptor part, a 3 legged looking thing, and coupled a larger hydraulic pump to it using a flexible joint and fabricated a mount for that larger pump.
That was about 10 years ago and so far no problems at all.
I mention this procedure as you'll find that it is much more economical to buy and adapt a generic pump than a Mitsubishi specific, especially for a grey.
In my case one of the FEL 'posts' was factory designed as a hydraulic reservoir making the modification easy.
NB, my factory pump now serves only for the 3 point and power steering (when I complete that mod)
All this is to say that the crankshaft and pulley was designed to accept driven loads.