Well
I myself a long time ago decided to use for TRACK as system of 0.0 which can be extended to 0.0-0, where 0 represents the number of disc and all that follows the . are the actual numbers of tracks on a given album; thus eliminating the need to use any kind of DISCS field. So for example Discosogs "Sandstorms" by Carl Craig described as 5-B would [most likely] be [as I have not listens to that album] described in my system as 1.9. and If I were to keep it together in one file with the next track "Squirrel Bait" by Daniel Bell], I would describe it as 1.9-10
Such approach of course would be hard to integrate with automatic download of tags from database and it has some limitations in regards to some formats [[X] Can't copy some unusual TRACK tags from MP3 / FLAC to WMA]