You are right, that is a step in the right direction. Maybe something similar could be implemented from 'right click/ auto-tag by track'.
Still, however elegant, personally I would prefer a more complete overview at once, without having to hoover over fields to 'unhide it's secrets'.
It seems Steven has a preference to keep those kind of windows as small and uncluttered as possible. (noble and defendable of course)
Maybe an 'advanced' button on those kind of windows could open a larger (full)screen window with more overview and options for the more advanced users. A dedicated full-screen layout with all tagging options in one view without several tabs or smaller and restricted panels would be great.