I use the cruise control and autopilot feature. The advance autopilot will not react fast enough to keep you on a straight line, if fishing over brush this will drop lines and keep them hung. Longlining is about covering water for aggressive fish, so long, straight pulls are better. Once you find good fish, you may have to change to shorter pulls if fish are tight to one area. Though, with most crappie in my area being Black Crappie, they tend to suspend in open water. White Crappie will also, but are more prone to some form of structure. It may just be a grass ledge. When you find this zone it is sometimes favorable to yo-yo fish by turning off your prop a spell to drop your jigs, then start back up after passing the ledge.