Gtk 4 has decided to blow up some people's world on HiDPI displays
In Gtk-4, it turns out that they removed support for GDK_DPI_SCALE but not GDK_SCALE (via this KDE bug report). This makes life decidedly awkward; I can choose between having decent sized icons and UI elements along with giant text, or reasonable text and tiny icons. Gtk-4 has a settings file (the personal one is normally ~/.config/gtk-4.0/settings.ini), but as explicitly documented it's mostly ignored if you have XSettings active, which I do because I need it for other things. The current Arch Linux wiki page section on HiDPI in X suggests that there is a way to override XSettings values for Gtk(-4?), but this doesn't work for test Gtk-4 applications for me.