If one of the reasons for extending the ball back some, is to Jack knife the trailer per say......the best way to fix this, is extend the tongue of the trailer, so you have at least 4',4.5' to the trailer body or part that will hit.
I've also found that the longer the trailer from ball to axles, is easier to control backing. As truck will usually out turn the trailer easier. I also prefer the pivot closer to the TV axle vs far behind for handling issues as mentioned by some too. Although, I have to admit, most of the.trailers I pull do not use WD systems.
My 02 on this.
Marty.
