Matching for multi-disc albums

[kavermeer]

I see; that is some implementation detail that I was not aware of.

Not trying to question your design choices, but from an end-user point of view, I do not really like to have to add [Disc x] to all album tags. All discs come from the same album, and it therefore feels more natural to give them the same name. It also makes it easier to ensure that they have the same name, because the tagging software shows the same album tag, rather than some indication that it's different for all tracks.