I think one of the biggest challenges for FOSS (that proprietary software gets right) is making an app work and look right when half of it is on a HiDPI screen and half of it is on a lower resolution screen.
Sad to say, once I could afford $2500+ HiDPI laptops, I became a lot less picky about running proprietary OSes...
From what I've heard (I don't use proprietary OSes), Windows had a lot of issues with HiDPI in exactly the situation you're describing. They also had scaling issues with having different resolution monitors.
Sad to say, once I could afford $2500+ HiDPI laptops, I became a lot less picky about running proprietary OSes...