... I bought a different brand of stop leak endorsed by NHRA labeled to serve the same function. I bought a 24oz. "Lucas Transmission Fix" which claims "Compatible with all transmissions and transmission fluids." as well as "Will not void new car warranties!" I figured this would be an acceptable alternate.
I would say my trans is now performing 95% without the additive. I may try the additive after more time to see if there is any significant difference but functionally it is working fine now. I feel I need more time both driving and aging to be able to say the Syn. ATF was all that was needed.
I will post again when I have more proof. Thanks for all the advice!
It has now been a few months since I had the ATF flushed, added AmsOIL, but left out the Stop Slip. Slowly over the last couple weeks the slip has begun to show again. It is subtle and still way better than it was before the flush. I will now be adding the Stop Slip, which I am confident will reduce the slip entirely.
I Will update with results.