I was going to write there is sort of an option for this in the 'Artwork' view (I take it this is in the 'Album and Tracks' layout?), there's a dropdown box called 'sub-grouping header:' where you can choose which tag to use instead of only Disc#. For instance, I have a virtual tag set up so that if the Grouping tag is "Podcast" or "Mix", the header will display the year instead of the disc (I have hundreds in some albums, don't ask
). But actually I've just checked and if you remove any header at all, it still splits by discs with an empty line, and my podcast-year thing only works when there is no disc number. So ultimately it would simply be nice to not have <Disc#> override all.