I have the same problem - 14 inch WQHD screen. I use 1x UI scaling, 1.6x font scaling. I also made a custom css for GTK that resizes window decorations/buttons that make them more usable. The solution is not perfect though. I am having some problems with Qt apps.
Fractional scaling on 3.28 will allow you to have different scaling for each display. Will also be more consistent across different apps (Gtk, Qt, electron, etc.).
Same, 2560x1440@14" scaling at 1.6.
Numix window decorations scale (where Arc doesn't) - I use Numix anyway so it works out, can't wait for proper fractional scaling since I'm a cinnamon user we'l likely get it around the same time.
Qt works fine for me. Have you set your Xft DPI?
$ cat .Xresources
Xft.dpi: 144
Xft.hinting: 1
Xft.hintstyle: hintslight
Xft.antialias: 1
Xft.rgba: none
Xcursor.size: 48
Xcursor.theme: AdwaitaThanks lima. .Xresources does not work on Wayland. In my case Qt apps work ok until I connect an external display. Here's before/after: https://imgur.com/a/bJb0J
Ow. Can't help with Wayland :(
It does work with X11 for me.
For users of older Gnome versions, note that you can change both the font scaling (text-scaling-factor) and global UI scaling factors.
If you, like me, have a screen that needs 1.5 scale, you can either set UI scale to 1 and font scale to 1.5, or UI scale to 2 and font scale to 0.5.
That's almost as good as real fractional UI scaling.