Well the squeaky wheel gets the grease rings true once more. I reached out to Sokek about my grievances with the current AI folding stock thumb rest design and I gave them some ideas on what I was looking for and they came up with a new one. I took the rifle out this past weekend and ran 100 rounds through it prone, off the tripod and on a table seated. I couldn't be happier about the changes.
The new design puts your thumb pointing forward instead of up near 1 o'clock like the last design. This allows for the palm of your trigger finger hand to rest against the side of the grip instead of just the butt of your thumb like with the previous design. My trigger finger now rests against the trigger shoe without strain and the wrist of my trigger finger hand is no longer under tension. They nailed it with this new design and like with most of their products it's an affordable option that's readily available.
With Sokek's permission here are a few pics of the new design for folding stock AT-X(C) rifles.