I take it your referring to a fishing reel that automatically moves the line left to right and back again. Thus making the spool evenly. As to your winch, no, since at times you might have to do a slight side pull a small diameter ring forcing the cable or nylon to make a sharp bend isn't a good idea. Any time you do a pull at an angle you take a chance of breaking some of the small strands in your winch cable. Over time this weakens your cable and makes it prone to failure down the road. You always want to pull perpendicular to the object your pulling, and during the pull you don't want to be near the winch face, in case a the cable breaks. its best to allow the cable to wind itself up, during a pull, then later respooling it after you are finished for the day. Any object that forces it to either left or right will put a small bend in the cable during a pull, something you don't want to do.
But this is an intresting idea...
