Keep or sell 2016 FL Cascadia DD15???

The last truck. 2014 dd15.13 manual..always had def issuers. I mean always. But then he plugged in a issues be gone cord and I feel in love with it. Put a couple hundred k on the odometer. He got that truck. With 489,511 miles ill never forget that truck.
Now to your response. This truck has a little over 380 k on it. Today was my longest run in it so far. 379 miles. No issuses so far. But this engine break and the super singles wow that took a little getting used to.
His plans are to run this truck very light. And on level ground. With only enough idle to cool the engine. Then running the apu.
The way I understand it is. Excessive engine breaking and idleing not on high rpm. Is what's Causeing the def issuses.

I don't know squat about diesel and even less about def/dpf. But hope I answered you a little bit.

Side note, my last company made us run engine break ALL the time running 40 coast to coast. And they always had def issuers.