I think a bigger issue is that native file dialogs are not used.
One of the problems following that, is the problem reported in this issue. Another problem is that none of the favourite folders, OneDrive and other cloud drives, etc are visible in the dialogs. The user not only have to learn new keyboard shortcuts, he also has to go through the trouble to sync favourite folders between native and Geany file dialogs. It is not a deal breaker, but it feels "clunky" and old.
Don't know if it helps, but found these two links regarding native file dialogs as part of GTK: [https://docs.gtk.org/gtk4/class.FileChooserNative.html%5D(https://docs.gtk.o...) [https://gitlab.gnome.org/GNOME/gimp/-/issues/1830%5D(https://gitlab.gnome.or...)
I wish I understood how to implement this myself, but I don't. Have tried the css files, but they don't seem to pick up when Geany starts.