I've been learning a couple things about my unit:

1. When setting an A-B, it is possible to set the A point and then change the B several times as you drive on the first pass that will determine the final A-B. Although you can set the B several times along the line, it only remembers the first A and the last B. If the B is set before you reach the end of the field, the A-B is extended automatically. What I do is set the A, drive far enough to set the B and then allow the EZ-Steer to take over for as long as my originally set A-B covers to the edge. If the field bellies inward, I drive manually. If it bellies outward, I drive manually until I get to what looks to be the furthest outward point and set the B again and then continue to drive manually until I can turn it over to the EZ-Steer. If I can drive manually without needing to go outside the A-B, I'm good. If I need to go outside the A-B, I set another B, etc, etc. Once you get to the end, you have an A-B that returning on will be straight, may overlap, but will leave no skips.
2. Surveyers screwed up when they set the pegs on my place so I can't set 0, 90, 180, or 270 and have things come out. I did make a pass from one stake to the next and set A on one and the B on the next. I then scrolled to the display that displayed heading but was disappointed to see that screen didn't display resolution in other than whole degrees. I noticed if I attempted to set an A+ immediately after setting the trial A-B, the suggested setting - displayed with 2 decimal precision was the newly set AB. All further A+ settings have had .13 degrees added to the desired direction and everything works great. My fences and stakes now come out perfectly. Of course if you immediately tried to set an A+ after doing the routine in 1, you would know the true heading but it wouldn't be possible to use that heading on subsequent times of working the field because you would still need to work the bows and bellies the first pass on the field. You could of course set an A+, drive manually where necessary, and then be ready to do the rest of the field and not need to set the multiple B points that were necessary in the 1st instance.