Great! Thanks for the quick confirmation. I’m a noob when it comes to any type of backup. I don’t know TimeMachine very well so I don’t know how to tell it to exclude something like the Roon Database. The simplest solution for me right now is to just not have Roon open and running when I do my manual Time Machine backups to the USB drive. Simple enough.
In the future, if I get myself a NUC running ROCK, then that will backup to dropbox or a separate hard drive and I won’t have to deal with the potential complication of Time Machine which will not be running on that device.