I have created a small script to list the packages needed to add an additional desktop to a default Silverblue desktop. This script has to be run inside a workstation-ostree-config repo on the branch for the corresponding Silverblue release. Here is a run for Fedora 32 with the current desktops I made a package selection for:
kde: breeze-icon-theme xorg-x11-server-Xwayland plasma-user-manager sddm kwin kf5-baloo-file kde-settings-pulseaudio xdg-desktop-portal-kde kinfocenter kwayland-integration kwalletmanager5 plasma-breeze ksysguard sddm-breeze plasma-nm glibc-all-langpacks dolphin polkit-kde qt5-qtbase-gui kdeplasma-addons plasma-discover plasma-drkonqi kf5-akonadi-server-mysql sddm-kcm gnome-keyring-pam konsole5 plasma-workspace-wayland khotkeys kscreenlocker pam-kwallet plasma-workspace qt5-qtdeclarative kf5-akonadi-server initial-setup-gui kwin-wayland xorg-x11-drv-libinput kscreen kde-print-manager kmousetool kde-gtk-config NetworkManager-config-connectivity-fedora bluedevil ark plasma-pa phonon-qt5-backend-gstreamer plasma-desktop kdialog
xfce: xfce4-datetime-plugin xfce4-settings bluebird-gtk2-theme greybird-xfce4-notifyd-theme bluebird-xfwm4-theme xfwm4 xfce4-about thunar-archive-plugin xfce4-taskmanager xfdesktop blueberry thunar-media-tags-plugin xfce4-session xfce4-appfinder arc-theme xfwm4-theme-nodoka albatross-xfwm4-theme gtk-xfce-engine adwaita-icon-theme adwaita-gtk2-theme greybird-light-theme desktop-backgrounds-compat greybird-xfwm4-theme albatross-gtk3-theme thunar-volman gvfs xfconf lightdm-gtk greybird-dark-theme gnome-keyring-pam xfce4-panel xfce4-places-plugin xfce4-pulseaudio-plugin albatross-gtk2-theme bluebird-gtk3-theme Thunar initial-setup-gui xfce4-terminal xfwm4-themes xscreensaver-base fedora-icon-theme nm-connection-editor xfce4-power-manager network-manager-applet xfce4-screenshooter-plugin
lxqt: breeze-icon-theme lxqt-config lxqt-policykit sddm upower falkon-kwallet lxqt-notificationd lxqt-themes firewall-config notification-daemon lxqt-panel network-manager-applet xdg-desktop-portal-kde falkon pcmanfm-qt lxqt-globalkeys lxqt-session obconf breeze-gtk xdg-user-dirs lxqt-runner lxqt-openssh-askpass openbox lxqt-qtplugin initial-setup-gui lxqt-powermanagement sddm-themes lxqt-themes-fedora libqtxdg qterminal fedora-icon-theme perl-File-MimeInfo lxqt-about nm-connection-editor ark breeze-cursor-theme
deepin: deepin-system-monitor deepin-editor deepin-desktop deepin-screenshot fedora-icon-theme deepin-file-manager deepin-image-viewer firewall-config chromium deepin-calendar deepin-calculator deepin-picker
pantheon: switchboard-plug-pantheon-shell contractor pantheon-session-settings wingpanel-indicator-session pantheon-agent-polkit wingpanel-indicator-notifications switchboard-plug-onlineaccounts gala switchboard elementary-icon-theme switchboard-plug-sharing wingpanel-indicator-power elementary-screenshot-tool pantheon-agent-geoclue2 elementary-theme switchboard-plug-about elementary-wallpapers wingpanel wingpanel-indicator-keyboard elementary-shortcut-overlay wingpanel-indicator-network elementary-music elementary-capnet-assist switchboard-plug-display gnome-session elementary-code elementary-videos wingpanel-indicator-datetime switchboard-plug-a11y elementary-sound-theme switchboard-plug-printers plank elementary-camera switchboard-plug-sound wingpanel-indicator-bluetooth elementary-greeter switchboard-plug-notifications switchboard-plug-mouse-touchpad switchboard-plug-keyboard wingpanel-applications-menu elementary-print wingpanel-indicator-ayatana switchboard-plug-networking elementary-photos elementary-calculator wingpanel-indicator-nightlight switchboard-plug-bluetooth elementary-calendar elementary-terminal switchboard-plug-applications elementary-files wingpanel-indicator-sound
mate: mate-themes atril-caja firewall-config caja-actions slick-greeter-mate firefox mate-power-manager f32-backgrounds-mate mate-session-manager libmatekbd blueberry mate-notification-daemon usermode-gtk f32-backgrounds-extras-base gtk2-engines mate-screensaver seahorse-caja atril mate-search-tool mate-disk-usage-analyzer mate-terminal f32-backgrounds-base system-config-printer-applet eom gnome-epub-thumbnailer libmatemixer caja-image-converter mate-screenshot mate-menus-preferences-category-menu mate-control-center nm-connection-editor mate-polkit caja-open-terminal mate-applets mate-desktop mate-system-log mate-icon-theme mate-user-admin lightdm system-config-language mate-user-guide gvfs-nfs mate-menus system-config-printer seahorse f32-backgrounds-extras-mate libmateweather gstreamer1-plugins-ugly-free caja-sendto mate-calc setroubleshoot mate-system-monitor mate-settings-daemon mate-backgrounds atril-thumbnailer dconf-editor lm_sensors alsa-plugins-pulseaudio pluma caja caja-wallpaper libsecret initial-setup-gui mate-panel mozo pavucontrol mate-dictionary mate-media gucharmap engrampa caja-xattr-tags parole network-manager-applet marco
And the commands to switch to KDE desktop for example:
$ sudo rpm-ostree install <packagelist>
$ sudo systemctl reboot
---
# login on a TTY
$ sudo systemctl disable --now gdm
$ sudo systemctl enable --now sddm
You may encounter errors such as package XXX is already installed. This is fine and the corresponding packages just need to be removed from the list of packages to overlay.
Don’t forget to set the Desktop type to Plasma / Plasma (Wayland) before login.
Enjoy you never outdated alternative desktop Silverblue system 