Update September 10th 2024.
Got my truck back out of the shop yesterday. They tested and found a faulty DPFE sensor. Part and labor not under warranty but my dealer worked with Ford to get it done since it was just after the transmission warranty work. So far so good all bucking and hesitation...
Update August 30th: the procedures outlined in the service report above have solved nothing. Still hesitating and bucking between 12 and 1500 RPM. Back into the shop on the 5th. Fairfield Ford continues to be very accommodating with it. More to follow.
I'm in the middle of this now! Full rebuild 9 days ago and paperwork said to give a week or so for computer to learn the new tranny. Still bucking and clunking second to Third 1500 RPM to 30 mph. Hate to have to go back in but they have to make it right! So far Fairfield Ford is excellent about it.
Update:
Complete trans main control was needed & done at Fairfield Ford who all were excellent! See attached N/C invoice. So if your young un is stumblin', rumblin' & bumblin' get it to the shop now to save 6k+ if you wait!
Thanks to those in this thread who offered advice