I exclude my Roon database from Time Machine as well. If it can’t be used to restore function in the event of a problem, why use the disk space? And, including it makes for large, relatively time consuming Time Machine backups. You can exclude anything you’d like from Time Machine by clicking on the Apple menu in the upper left hand corner of your screen and choosing System Preferences. Choose ‘Time Machine’ from that screen:
Click on ‘Options’ in the lower right hand corner of the window:
Click on the ‘+’ and navigate to your Roon folder. If you’re not sure where that is, read this.
Good luck, cheers!