Take a 12" shock, with the preload set so static sag is 2".
Shorten the damper rod so the shock is now 10" full extension. Adjust the preload as before the shock will have the same 2" static sag.
Both shocks, same weight applied, same spring rate. Preload adjusted for the new damper length.
OK so you need to bear with me on this as I get a bit OCD around understanding things !! I get what you are saying so I guess the first thing is
Do you agree once static sag is set that the limiter on the damper rod is no longer effecting the rest position (height) but that it is the stored energy in the spring that is determining this ?
therefore if you wound off the pre-load adjuster to the same position on the shock body of the standard damper the rest positing determined by the stored energy would be the same but the static sag would be excessive ?
That being the case surely the purpose of shortening the damper rod is so that at full extension with the pre-load adjuster in this raised position that the spring doesn't become dislodged as it would no longer be in contact with the adjuster ?
It kind of all comes back to "the spring determines the rest position"