Personally I haven't seen any of the 2019 models, but uniformity is typically unaffected by settings. Determining something like gamma performance at Best Buy would seem pretty tough to me, since that would be affected by settings, yet it should be possible to spot some uniformity issues in a store. A lot of the manufacturer test loops are shot to make it difficult to determine uniformity issues like dirty screen effect. On the other hand, cable TV or a store loop could make it easier to pick out poor uniformity.
The last time I shopped TVs, Best Buy used to run a loop with a lot of solid yellows and blues, and some of the TVs on display had clearly worse uniformity than others showing the store feed. After specifically trying to rule out TV models with poor uniformity, I still ended up receiving a TV that had poor uniformity. In the end I kept it, simply because I found it less objectionable than some of the issues from other TVs. I'd certainly like my next TV to have better uniformity, so I'll again rule out TV models where I notice uniformity issues in a store.