Hi, is it safe to delete both full and database only backups from my devices once they have been restored? Or will doing this delete all the song files and work? In addition to this, if I want to add many more song files, do I then do an additional full backup and restore to my other devices or will this duplicate everything?

    LynnMarie yes you can delete all backups as they are a duplicate of your ST3 .
    I always keep them outside my ST3 folder just incase I have to restore ST3 the contents of the ST3 folder get erased, so it’s safer having your backups in another folder.
    Adding more songs requires you to update your backups then use them to restore other devices this just restores all the files and includes all your additional songs.