Joe yes I bet you have got your ROI. How often are you changing your oil?
Maint. Log driven, I change oil based more on a SOTP thing of what I've put the 2K through as far as Work'n it goes...but it comes out to: Oil & Filter every 6 to 8K, mileage wize...the Premo filter every other oil change.... Prolly Over-kill with a by-pass setup by some standards, but I go more on USE and TIME than Miles. Use More than Time I would say.
Synthetic or Dino.. I've alwayz been a believer that: A consistent Oil & filter change based on Time, Miles or yer own Duty Cycle..... is the BEST thing you can do to get the Max life out of whatever you drive, Gas Or Diesel.
Add additional filtration ? It's as Good as it Gits and Yer Good to Go.
My think'n on it
Joe