Most issues should be worked out by now.
I would ask to see the maintenance history. Have them pull shop records for the VIN to see what was done. If this isn't a RAM dealership they should be able to reach out to one to get the info. The dealership is the owner of the truck so can request that. The "early" 2019s seemed to be a little more problematic (built before 10/18) but the whole MY was the "first" in the generation so there were bound to be some growing pains...mine did (2019 that was in the shop 12 times in 4 years). The truck is pre-COVID so that's a plus.
I would inspect the rear window and surrounding headliner. There have been leakage issues (shark fin antenna, 3rd brake light, rear window frame) and the headliner is a tell-tale (stains) for those issues.
Check the entire circumference of the rear window for any cracks (especially around the sliding window frame portion in the middle). That is a sign of a faulty window frame that will need to be replaced. The truck is outside basic warranty so that is a $1800 - $2000 repair as the whole rear window has to be replaced.
The rest are small things that aren't really a "thing" to watch for. Just listen when you drive and touch all the buttons and knobs to make sure they do what they are supposed to...including the 4wd (there have been issues with the system ranging from electrical to mechanical).
Good luck!
