Kdog might correct me but my understanding is:
The cable going to the trans is for oil pressure regulation if you remove it you could set it at a possition and the oil pressure would be constant.
talking to MV automatics in adelaide if you remove it the pressure is set high which gives a relatively harsh change i have not driven without it but was told that is is not nice and should be retained. the oil pressure is relative to throttle position so you get the harder shift when your foot is down. if you can retain it would give seemless changes at low throttle position and quicker shifts at full throttle.
Good luck some one could remove thers and try it
I would but mine is not exactly running at the moment.