Hey all -- I wanted to circle back on this thread to be sure I gave a shout out to the DS team. I sent my tuner in for evaluation / refund -- the team performed a thorough check and even installed on an RHO for a week. Bryan (Master Tech as DS) has been 100% concerned their product was checked ok. Their communication has been nothing but STELLAR. On my side, I made an appt. with the dealer and uncovered what appears to be the root cause; the dealer confirmed my truck has a throttle pedal voltage issue (erratic voltage signal) with the throttle pedal "APP Sensor" which is also affecting the start / stop function. The start / stop hasn't worked in 1300 miles. Since DS tested on their end and found no issue, and I've done the same thing but found a problem, we could likely conclude the erratic voltage signal affected the DS product or even enhanced the negative aspect the faulty signal produced. The issue I had seems to land squarely with RAM, not the tuner.
The dealer had to order parts -- after the replacement, I'll test for a week, then reinstall the CAT6 (DS is sending me another). FWIW, I've learned (without tuner installed) that if you have this loss of throttle issue, you can put your foot under the pedal and pull up and hold for a few seconds -- this clears the issue and normal throttle resumes -- I've performed this twice now (while driving).