The big overall anwser is YES, As you are running you headleads and spraying it will log that coverage area, so that when you come back into your headland it will shut it off.

For your next question, as you go to reset Guidence after you select what patten type there is a screen that asks if you want to reset coverage area (or something like that) say yes and you will have you coverage map from the last guidence pattern, and everything will be smooth sailing. and it will pay for itself very quickly.