Thanks guys. I really appreciate your feedback. Some of the folks on the FB page were helpful as well. From a logical perspective, the only argument that makes sense is keeping the oil clean.
I suppose I could just do nothing and wait for it to fail, but that would guarantee that the transmission will ultimately be doomed.

My flush at the Isuzu dealer was 13 years ago (18K miles). So the fluid is old now. I hear you when you say that it doesn't get "old" but it has been a long time. I know the filter was never changed so I thought at 55K, now would be a good time. Since there isn't a maintenance schedule for a "normal driver" using the "severe driving condition" schedule seems like a viable alternative. On that schedule I would be changing the fluid every 20K. Like ipd, I'd rather change too often than not often enough.

One of my greatest concerns is making sure the fluid level in the transmission is correct. Since folks aren't actually measuring the internal fluid temperature and are just estimating, I am wondering if their problems could be traced to overfilling or under-filling. I liked the idea of using an infrared thermometer but here is a video showing how different the temperature can be:
https://www.youtube.com/watch?v=dPrP4NQZg6w
Time value 22:35 to 23:10
Perhaps if he used a thermometer with adjustable emissivity he could have retrieved a more accurate reading (the pan is shiny).
As of today, I still don't have an accurate way to measure the internal TFT.

If you want to see something really crazy, watch this one:
https://www.youtube.com/watch?v=cNcecuGzTDg
All of this complexity because they did away with the dipstick.