I would say I am in the middle range of wrist versus arm. I move at the elbow a fair amount when strumming but when picking out individual notes, it’s mostly wrist. I don’t have any good recent videos, but below is an older video I did to review a guitar. The playing starts at 1:46. The most “flatpickish” stuff I do starts about 4:10. Please take a look and see if you spot any problems. The biggest differences between how I played then versus now is that I typically play quite a bit closer to the bridge and my arm and wrist are a bit more elevated.
I still haven’t gotten quite comfy with the classical position, but I think I could see some benefits with that approach. Thanks for the help!