I read on one of the Windows 10 Creators Update articles which talked about this sort of thing, that Microsoft was still basically unable to fix the high DPI scaling, and was particularly disturbing given the Surface Pro 5 is supposed to ship with a UHD display. Glad I paid extra to get my Surface Pro 3 with Windows 8.1.
Lots of thanks for this. Was quite annoying.
fwiw, I stumbled across this because of cross-post in an issue where 17.4.3 Radeon version and Creator's Update enabled HDR, triggering TV profile to over-sharpen text causing a ton of halo-ing.