I've long ago resolve to just agree to disagree with Kev on this one, but it's worth raising the following as a thought experiment: How would some of these epics be done if it was possible to include "subdivisions" of a particular track? Like, if there was some added feature in music players that enabled "bookmarks" to be placed in certain songs, such that, say, 2112 is still a single listing on the album and plays as a single track with a 20:33 runtime, but there was also a place where you could select to go straight to 6:45, the beginning of "III. Discovery," etc. I think in that circumstance there's little question that SDOIT and The Whirlwind would be listed as single tracks, because MP has been pretty clear about the fact that he only split them up for ease of access.
Another interesting case is Coldplay's album Viva La Vida, where multiple tracks have two distinct songs inhabiting a single track. Like, a song plays, it ends, there's silence, and then a different song plays. The band regards each of these instances as being two distinct songs. But they included them on one track in each case as part of some artistic statement or something that is not very clear to me.