Hello!

I suggest adding an option below "Preserve timestamps of tagged files" called "Only touch timestamps of files that have a change in their metadata and/or cover". This will be an easy way to distinguish which files have been changed (for example new cover photo was added since last scan and the current scan downloaded it, or updated artists and MusicBrainz etc.).

Curently, the workflow is this one:

1. You load the files on the left
2. You scan the files, they move to the right
3. You mark all files to the right with Ctrl + A and use save. All files's timestamps are touched. Even if no change in metadata to already tagged files. How can you know which files to copy to phone/replace if you have 1000 of them?