I know that ATA is axle to axle, but is that when the bow is drawn and the limbs are flexed or when the limbs are relaxed and the compound bow is undrawn?
It looks to me, looking at the diagram on this site, that ATA is a measure of the bow itself. I would say that the limbs of the bow are relaxed in this diagram. I hope this article will also be helpful to you.
And here is the article: Understanding compound bows, and how to select them.