[Richard Morse]

I did a test:

Samsung NU7100 TV 
YouTube on Xbox One S -- YouTube on Samsung -- YouTube on mi Box 3

Chose the LG title 60fps with the butterfly (28 secs in)
Here we go three different results:

Xbox - no support for vp9.2 would only let me play at 1080p HD using AVC1 -- didn't even give me the option for vp9 -- used a 3860x2160 viewport - 
(the same xbox has no problem playing 30fps 4K titles in 4K using vp9, no idea why it won't select vp9 for ANY 60fps title)
Samsung internal Tizen - Perfect, displayed the vp9.2 - used a 1980x1280*2 viewport
mi Box 3 - did not use vp9.2 at all, displayed 2160p using vp9 - used a 1980x1280*2 viewport