The service department at my dealership updated the firmware in the Aisin Transmission Control Module of my 2019 Ram 3500 per
TSB 21-041-19. The old TCM firmware version was 68288452AK, and the new firmware version is 68288452AL.
My first impression is, the shifting has improved, but it still could be better. For example, when driving 60 MPH in non-tow mode and the exhaust brake disengaged, I can take my foot off the accelerator and the truck will naturally slow down by downshifting one gear at a time from 6th gear all the way to 1st gear. The downshifts are very smooth; the truck doesn't jerk at all. However, if I do the same test in tow mode (with the exhaust off), the truck will
downshift from 5th gear all the way to 2nd gear causing the truck to jerk. If I was towing animals in a trailer, it would be an unacceptably rough downshift which could cause the animals to lose their balance or impact the trailer.
The update did seem to improve the downshift from 2nd gear to 1st gear when not towing. Before the update, the truck would downshift from 2nd to 1st when the RPM was too high resulting in a jerky downshift. After the update, the downshift from 2nd to 1st seems to happen at a lower RPM, so the truck doesn't jerk as much. I haven't tried downshifting from 2nd to 1st while towing a trailer, yet.
Overall, the TCM update helped, but it still isn't as smooth as it could be. I will record some videos of the rough shifting so I can show them to the dealer to start the process of getting the issue addressed by the Ram engineering team.