I am not sure if this is helpful...I have a Gammill. You start at the left. I think I Have a 22 inch area to quilt (I have an Optimum. Once you have started on the left, you continue to your right but you can go sideways, up down left, right, circles or what ever, untill you end up at the right and finished with that section.
Then you push the machine back to the left side and roll the fabric up and start again. I think that is what is meant by starting on the left.