Kinoite shutdown/reboot from main menu don't work

Kinoite 36 in qemu/kvm
Shutdowns, reboots and logouts from the main menu don’t work. They just hang for a few minutes. However, systemctl poweroff and reboot from the command line work without any problems.

I think I know what’s causing this. I disabled XWayland by copying /usr/lib/systemd/user/plasma-kwin_wayland.service to ~/.config/systemd/user/ and removing --xwayland from the ExecStart line, because I don’t want top-level X clients (for security reasons, I will be running nested kwin_wayland windows with --xwayland for any X clients I need). Apparently, the shutdown/reboot/logout dialog is a obligate X client. I think this is due to using sddm, or the way it is configured in Kinoite.
Looking at /etc/sddm.conf and /etc/sddm.conf.d, it doesn’t look like any attempt has been made to integrate sddm with wayland - there are no non-default settings.
Does anyone have a kinoite sddm config that uses Wayland for its dialogs?
The Arch wiki suggests it’s possible:

I found a config that works:


CompositorCommand=/usr/bin/kwin_wayland --no-lockscreen

based on:

With this config in /etc/sddm.config.d, after doing with the Arch Wiki entry said about the Startup and Shutdown options, sddm uses Wayland from the start, and no Xorg remains running on another tty (as one does normally when starting a KDE Wayland session in Kinoite).

However, the shutdown/logout/reboot dialog is still trying to be an X client, so this does not resolve the original issue. Is that an sddm config setting, or part of KDE itself?

The problem is the KDE exit confirmation dialog is X-based. If I disable that by going to System Settings->Startup and Shutdown->Desktop Session and unselecting Confirm logout and Offset shutdown options, then I can shutdown, reboot and logout using the main menu.