I notice that I’m losing disk space, I recently had about 12% free on my Mac, and lately, it’s been disappearing. I’m now down to 8% even after deleting large files and unused apps.
I looked at the activity monitor and found that Roon had written nearly 17GB.
If you are using the Nucleus as your Roon Core, I would not expect that your ~/Library/Roon directory would be that large since the Roon Library is being stored and maintained on your Nucleus. In this setup, Roon.app on your Mac should pull all of its data from the Nucleus, storing at most a few GB of data for cache purposes.
Did you use the Mac as your Roon Core at one point?