What you must remember is that this motor has over 9000 hours on it already, I figure that is about 450k in road miles with little or no rpm changes (2k consistant). So for the readings and age I believe it looks pretty darn good, the oil is still a amber colour (slightly dirty now) but I see no nbeed to add a bypass.
The Auto RX filter change was after first 10 hours, no gunk or buildup...then went an additional 200 / 210 hours with no visible gunk or buildup ( I even checked the used oil and it was not bad). I am not running a maintenance dose due to simple economics, I may however do a treatment every other year??
I hope to get another 325 hours, if so that will extend oil change almost twice....at $3.80/gal for off road it is money in the bank.
I also have this same oil for 2006 CTD..anxious to see results