If your issue is related to X11 scaling you should open a new issue or modify the topic description.
There are some threads on high screen resolution but no perfect or easy solution when you are using multiple different screens.
You need to modify DPI, scale factor, GTK settings and font size. Here are some variable you can try and see if it works for you.
QT_AUTO_SCREEN_SET_FACTOR
QT_SCALE_FACTOR
QT_FONT_DPI
GDK_SCALE
GDK_DPI_SCALE
When you are using Gnome:
gsettings set org.gnome.desktop.interface text-scaling-factor