What triggers a Media Library update?

I have been updating some of my mp3 and FLAC file tags and it seems that the Media Library isn’t showing the changes. I have my files stored on a Sharespace NAS. I have tried switching the Media Library off and then on to force it to recompile, but the information doesn’t update, even though I get the message that the Library is compiling. If I clear the Media Library the changes appear. Am I just being impatient and the changes will eventually show up or is this unusual. It seems that I’m having to clear the Media Library more often since the last update. Or maybe I’m just changing my files more often now.

Turning it on and off doesn’t do a recompile.   It just scans for ADDITIONS and DELETIONS, as far as I can tell.

To force a recompile of EXISTING media, you’ll have to CLEAR the media library.

That’s bad news. I am going to be updating a lot of my audio file tags, so it looks like I will be clearing the Media Library a lot. Would it add a lot of overhead for the Library to check for updated files that already exist?