Roon ready...? Or how to regulate the volume?

Depends on how Roon has been setup on your NUC. If your NUC is running Rock, the you would need a separate environment on which to run the extension.

I have my Roon extensions running in Docker on a Synology NAS, but you could also use something like a Raspberry Pi.

If you do decide you want to try extensions, you might also want to have a look at the Roon Extension Manager, which s an extension that allows for easy installation of other extensions.

If you are not a technical person, then there is RooExtend, which is a commercial solution for running Roon extensions