I really dislike using a straight AB line in my land, as every feild here tends to be triangle or diamond shaped thanks to grid roads that run about 30 degrees off from the natural lay of the land.  Custom operators don't seem to be capable or willing to figure out the actual angle of the longest straight side, so just go straight NS or EW and make triangles all the way.  Usually finishing up making extra tracks on the longest run instead of the shortest.  I find it much more efficient to just use freeform and follow the longest nearly straight side( I don't have auto steer).  

So, my question, can you do the outside round, then ask the GPS to figure out the most efficient way to do the rest, with the least number or turns at headlands, and the shortest distance to overlap on the final pass?  I realize the row crop folks probably wonder what I am talking about, this is all small grain and spraying or fertilizing can be done in any pattern or angle.