I use MP3TAG for quite some time now and one thing annoys me since the first day:
When I acquired some new music I usually tune into it right away. I know and understand that MP3TAG cannot (and should not) write file changes while it's in use BUT ever so often I have to manually redo commands that failed because I wasn't aware the file is in use.
My idea/request/plea for mercy: How about a button/shortcut which applies the last 3 actions to other files?! Like in Microsoft Word F4 does with most formattings. That. Would. Be. Grand.