go back a bunch of pages and we had an extensive discussion of this - you're talking about two different methods of measuring droop - dynamic and static droop.
don't really want to go back into detail, but dynamic droop can change, because it's dependent upon ride height, and static droop does not, because it's dependent upon chassis measurements.
AE (and others) suggest static because it's easier for most people to grasp.
Both work. Both are valid.
