It seems that importing album art from Discogs by using the quick Discogs button has some - not critical - issues:
- The Quick art (Artist+Album) button for importing art, is somehow connected to Discogs submenu. I've noticed that it inherits the last selection of the Discogs submenu, i.e. if the submenu has been used to search - for example - the cover art only by album (selection Discogs -> cover art -> Disgogs) the next quick search is pinned to the "album" field only without showing the artist field. The exact same thing happens if the Discogs submenu has been used recently to import tag information (i.e titles, album, artists etc.) and not just album art. The next "Discogs quick art search" is pinned to the last selection of the Discogs submenu.
- In the later case, i.e. if the Discogs subfolder menu has been used to add information (and not just the album art) the next time the quick art button is used, all relative information is inserted (i.e. titles, album, artists etch.) and not only the album art. So somebody has to be extra careful because if every other kind of tag information has been inserted by hand and the quick button is used to just enter the album art, the already inserted information might be modified by the discogs connection.