I don't plant across waterways like that, but I bet that can be a surprise if you're thinking it's going to go straight across and whips you sideways when you hit resume on the other side of the waterway!!
I still try to have the straight A/B line that I used for planting ready to swap to, in case I don't like where it's going to take me. I have mostly square fields and sometimes will count the number of passes left to spray so I know how much to fill up to get as close to empty as possible when finishing up. The Autopath lines aren't numbered, so I can't use them to help count the passes left. Minor thing. I wish AutoPath would show in Op Center and allow you to select where the overlap is in a field.