Yes I think it is a genuine concern that IF something goes awry with the US then you need backup. The US can provide this in either wav or flac format as detailed many times above.
I would make sure you have a back up of your music somewhere. If it’s in wav format it can easily be re tagged using Gari’s instructions.
Just bear in mind that if you make changes to the metadata in the Unitiserve Music folder using a third party app you will break the database and probably cause problems further down the line. You could take a copy and do the conversion on that, but of course you will not then have FLAC copies of any new additions to your library.
If you just use the Unitiserve and it’s automatic backup as intended none of this stuff needs to concern you.