I don't have any issues using multiple displays with different scaling settings on Linux.
Pop! OS, Ubuntu, and Linux Mint are among the distributions that flawlessly accommodate different scaling settings for multiple displays without any special adjustments.
On Wayland, both the GNOME and KDE desktop environments support multiple scaling factors.
For GNOME on Wayland, if you need fractional scaling, you'll need to turn on a setting if your Linux distro doesn't do it for you:
Pop! OS, Ubuntu, and Linux Mint are among the distributions that flawlessly accommodate different scaling settings for multiple displays without any special adjustments.
On Wayland, both the GNOME and KDE desktop environments support multiple scaling factors.
For GNOME on Wayland, if you need fractional scaling, you'll need to turn on a setting if your Linux distro doesn't do it for you:
https://www.omgubuntu.co.uk/2019/06/enable-fractional-scalin...