Found some new stuff while poking around with the blurred pictures.
Still with the 2018 MacBook Pro 15” intel UHD 630/ATI Radeon Pro 555X with LG Screen
1.Color profiles to make a difference - the default profile (color lcd) is a lot smoother than say Adobe RGB1998 - so the older Adobe1998 might have less dithering. Who knows - but it does produce more color bands.
Link to video
2.With both True Tone OFF and Night Shift OFF the display adds like an additional dithering layer when either of them is turned off (and the other one is off as well)
Link to video - notice the black color bands on the left changing, stoping and after a second the final pop of smoothness.
3.ATI is the devil indeed. When running the display with Intel I see more bands (maybe this means less dithering) but with ATI enabled - everything is smoothed out - means more dithering I guess.
Will try to do a full workday with this new configuration soon-ish and see how it holds up.
The integrated LG display on this model is sluggish as hell though, so even a couple of back and forth swipes in that place where all the app icons are is making me puke 😃
Also this has got me thinking that maybe the 2018 15” are ok cause they have only Intel stuff and with older color profile and nightshift on (not for the yellow tone but somehow nightshift removes some dithering) that they might be ok.
Maybe someone has some newer MacBooks they can test this out on. 2015 or 2017 ones.
Steps to reproduce all of the above. - open Spotify web player playlist (it has this nice gradient there) and mess around with the display settings (eg color to Adobe RGB1998 or default), TrueTone on and off (with adobe color profile and nightshift off at the same time) and performance settings Automatic graphics switching on and off.