Any particular reason why the Flatpak recommendation in Budgie Welcome doesn’t go with the official PPA? That would also let you add the gnome store integration (gnome-software-plugin-flatpak) and add Flathub as a source for apps.
gnome-software-plugin-flatpak is already in the official bionic repos - welcome installs the following when flatpak is chosen:
"flatpak", "xdg-desktop-portal-gtk", "gnome-software-plugin-flatpak"
Bizarre. I did a double-check of dpkg -l before posting and only flatpak and bubblewrap showed up.
packages.ubuntu.com is very useful for searches!