2017 Burb here closing in on 100k with a lot of performance mods (she's got a little abuse on her)
Get a tuner (either a "canned tune" like an Edge programmer or remote tuner like BlackBear) to disable AFM and DOD.
When you get your transmission fluid changed, there should be a bulletin on the transmission lines that go to the radiator. If not - upgrade them to the newer style. While that's getting done you need to modify the Thermal Bypass Valve - you can either "flip the pill" like
@shock said, have it removed, or buy and elimination kit (
https://transgo.com/product-details/6l80-cooler-bypass/).
If you buy a truck with the 8 speed - replace the torque converter with a known good brand - Circle D, Yank, Etc. Its not for performance's sake - its transmission longevity sake.
Plan on replacing the battery ground cable. I recommend doing a "big 3" but replacing at least the ground cable with a new 0/2 gauge wire would be a big improvement. The ground cables are known to corrode from the inside out. So the battery terminals look fine but the cable inside the sleeve is more green than the Statue of Liberty.
Replace all fluids and filters early and often. If you live in an area where the leaves/pine needles fall, do that cabin filter asap.
I change my oil every 3k, trans & diff fluid every 25k. Check the filters every 10k. I have had ZERO issues with my truck other than the ground cable. I've modded the crap out of my truck and drive it like a Corvette (drag strip and autocross) and outside of a couple flat tires, its been rock solid.