Your interest and involvement
Just interested in having it as it would be nice to move all infrastructure to Ubuntu (I’m currently running OSMC on a Pi. Sidenote: OSMC does not officially support booting from USB/external SSD. Given the speed/reliability improvements, this would be a huge plus if possible as an appliance)
Kodi is a free and open source Media Center. There is a mir-kiosk-snap from Alan Griffiths (https://snapcraft.io/mir-kiosk-kodi)
As for other snaps I’m not sure.
The appliance should work on ARM and x86. Only an external monitor and sound out is needed for normal usage. Support for (USB) remotes would be nice, but is not a requirement
Should use existing maintenance infrastructure as kodi debs are available from Ubuntu.