Maybe as a second input to your question: I'm using foobar2000 as my player, which is very customizable. Your range of freedom might vary if you want or need to use another player.
As an example, I'd configure the Tag Panel to use the following fields:
-
TRACKandTOTALTRACKS -
DISCNUMBERandTOTALDISCS YEAR
Since FLAC/VorbisComments prefer TRACKTOTAL and DISCTOTAL, I'd add corresponding mappings via "Options > Tags > Mapping" (next to the existing one for DATE and TRACKNUMBER)
| Tag | Source | Target |
|---|---|---|
| VorbisComment | TRACKTOTAL | TOTALTRACKS |
| VorbisComment | DISCTOTAL | TOTALDISCS |
Since ID3v2 usually has the totals in TRACK and DISCNUMBER, this configuration creates two custom text fields TOTALTRACKS and TOTALDISCS. I'd find this acceptable, especially because I could use the separate fields to create a combined one (if necessary).
Since you've mentioned ID3v2.3, but already noticed that Mp3tag is flexible w.r.t. the YYYY restriction of the TYER frame, I'd put the data here. MP4 and FLAC are also fine with that.
This is only an example, but would create a configuration you can use for the mentioned file types without distinction of the actual file type when filling the fields. All under the premise that you use a player that is flexible enough to display the data.