I installed the minimal version of KaOS in Calamares, and installed kde-gtk-config by hand.
Is there anything more to do, to bring it to show up? Restarted systemsettings, ofc.

Screenshot

Systemsettings > Appearance > Application Style > bottom right Configure GNOME/GTK style

    demm Oh, wasnt that its own menu? With lots of more to configure?
    Thanks for the help 🙂