I’m not sure that sharing IN Roon would be all that smooth. People use different services which are all region restricted. And, how do you share stuff in your library that has no equivalents in the streaming world.
If you want to get an idea of how it could be done, then install the DJ extension and join us on the Roon Discord channel. You will begin to appreciate the hidden potholes that crop up in discussing this stuff. Rugby's Lunchtime Discord Album Show