I’ve recently added the DVD disc for https://musicbrainz.org/release/263dc163-652d-49c8-b6d7-072f9971562f which contains video recordings for each of the tracks on the CD, plus a making of documentary. Should the documentary have a track number? It’s not part of the main playlist, so I’m thinking not, but I couldn’t find anything to suggest one way or the other.
On DVD, you have several TITLEs, which contain several CHAPTERs.
You can number them like TITLE.CHAPTER (1.23), for instance.
But it’s also perfectly fine as it currently is, with only an incremental track sequence.
There is no rule.