The ability to specify the tags you'd like applied to all tracks, and remove/clear any that aren't on the list. For example, if "Comment" isn't on the "allowed" list of tags and the track contains the "Comment" tag (with data in), an option would clear that tag, and remove it (if possible).

Things like "Encoded By" etc are annoying tags that just add bloat (IMO). It would be nice to have the ability to strip these tags automatically.