Roon requires an internet connection. At the moment you can go offline for about 30 days – this is mostly driven by metadata licensing requirements.
For example, we must report to copyright authorities every month on how many lyrics have been viewed, and which lyrics those are. It’s so that royalties can be paid to the lyrics authors. I guess we could turn off lyrics if you don’t have internet access, but that is lame.
It is not on our roadmap to change this requirement.