I have the Window Behaviour action for middle-click on the title bar
set to "Toggle raise and lower", but some GTK-3 apps ignore this
setting for certain windows. One example is the Compose window in the
Evolution groupware suite.
To see what I mean, try the gtk3-demo app (from the gtk3-devel package)
which also shows this behaviour under KDE but not under Gnome.
poc
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