so sorry this brings up another question regarding sag vs middle and rear ride height. (I had always equated rear sag with the difference between the middle and rear ride height, so in your case that would be around 0.5mm sag due to the 3.4mm mid and 3.8mm rear ride heights).
what measurement does one get 1mm sag from? if you measure sag from the upper travel limit to static ride height, then it would be closer to 2mm?
Sag is difference between the static center ride height and the center ride height at full extension of the shock. Basically... measure the center ride height, then pull up on the top of the shock or antenna, and re-measure. The difference between the 2 measurements will give you your chassis sag measurement.
I typically measure the pod droop by placing the car on droop blocks and measuring from the pit board to the rear edge of the pod plate with a pair of calipers... then subtracting the height of the droop blocks.
Using this method to measure droop has pretty much always left me with pod droop and chassis sag measurements that differ by just a little bit. But the exact #s aren't as important as making sure A) you have
some sag in the car, and B) that you measure the sag/droop the same every time, so you can compare from setup to setup/change to change. If you have 1mm(+/- .5mm) of droop and sag, you will be in the ballpark.