I have spoken to Patrice at length about it on the phone. It was designed that way because that is what the military wanted. Cadex did some experimentation for me to see if they could make their trigger work the other way, but it was not possible, unfortunately.
They were able to get it to work with a 2lb. first stage and a 1 lb. second stage for a total of 3lbs. Normally, their second stage cannot go below 1.5 lbs.
On the CG Xtreme, I only needed to change out the first stage spring to get a heavier first stage. The second stage did not change from 8 oz. when I did. I now have 2lbs. 2oz on the first stage, for a total pull of 2lbs. 10oz.