Just changed our trans fluid on a 2014 promaster 3500 motor home with 21000 miles, also installed a dormant pan, i used Mopar filter and trans fluid, no problems shifting or oil leaksI did the 105 inch pounds as el jefe suggested with a crisscross type pattern. I replaced the trans pan tonight with the dorman one with a drain plug and the felpro gasket. Everything seems to be good so far as far as leaks go.
The van is a 2018 1500 136 wb high roof with 32k miles on it. I got it towards the end of september and put about 2k miles on it. When shifting into first it is not as smooth as I would like and thought a fluid and filter change would help. It did a little. At this point I am going to keep on driving it and monitor it to see if it gets worse.