My wife’s 2005 Acura MDX called for a transmission service that entailed draining the transmission, filling, driving, and then repeating 2 additional times for a transfer of 9 litres. I simply drained the transmission every second oil change and refilled (3 litres each time) and the fluid was like new right up until we sold it this past spring. So for the Ram I would do the simple drain and refill as per the book (or more often if it makes you feel better) and call it good.
And it’s very easy to get a full drain and refill on my G56 manual truck! :B