Hi, > I am somewhat at loss for how to proceed, unless Gtk+ devs themselves come > up with a standard solution.
I don't think they'll do so. They love their CSDs and apparently don't care much about other desktop environments besides Gnome Shell. We can expect some help only from Debian Gnome maintainers (though I don't know why no one of them replied yet). BTW, Arch Linux guys already made use of your patch [1] (they have an older version though). So far, there are no comments on missing application-specific controls that were located on the headerbars before. [1] https://aur.archlinux.org/packages/gtk3-noforcedcsd/
