OSMC as upnp music renderer

I’m using a Pi 3b and HiFiBerry Digi+ Pro audio card. All of it works fine and seems to be quite reliable.
I am only using this setup as a upnp music renderer, with bubble as the controller and MinimSrever on another Pi as the server. This also works quite well, and makes for a relaxing end of day. In this situation, a monitor and input device are un-necessary.
However, OSMC seems to require some sort of input device connected to it to boot properly, so I have an old mouse hanging off the side.
Disabling mouse in settings allows the setup to work headless for CD quality music but HiRez music will no longer play.
Can someone offer help in how I might edit the config.txt file or maybe blacklist something so my Pi can boot without an input device connected?
Thank you.