I don’t have any advice on the DeWalt as I use the Makita. But, after reading several stories about losing brushes, I looked at mine. They were still very good. Then, I went on EBay and bought a cheap little “timer”, about $7, and wired it into the X-Controller power bus. See photo. Then, I added an item to my PC calendar to “check the timer and/or the brushes” periodically. I don’t have any data yet to say how long my brushes will last. I did order a new set so I wouldn’t have to be down for several days.
I’m just a hobbyist, (no business), but I would guess that “ordinary” routers and vacs are just not designed to run continuously for hours every day and be expected to last forever.