There is a problem with track sorting when I browse my library. I have many 2 in 1 CD’s that are tagged with track number on CD and album name according to original albums. What is confusing - in browse window songs are sorted alphabetically by album and then by track number - so in some cases track order is mixed, but if I add complete folder to playlist they are added correctly by track number. It’s not a big problem but little confusing.
I don’t think Volumio uses tags.
What I do with double albums is use numbering to distinguish and order the tracks
\Some Band\An album
01 A song.flac
02 Another song.flac
03 Quite a good song.flac
04 Song after some others.flac
201 First song on CD 2.flac
202 Another song on CD 2.flac
203 Slow song on CD 2.flac
204 Best song on CD 2.flac