Another strategy should be to use a variable displacement pump.  If the pump is configured for low displacement, it provides a reduced volume of oil circulation, leading to the hydraulic motor(s) to turn more slowly and gradually. Like most automotive technological know-how, you can find advantages and disadvantages to CVT gearboxes https://gearboxcvt17272.blogunteer.com/33153532/a-review-of-gearbox-cvt