This has been brought up several times in the forums but nobody seems to have made it a formal “feature request” so I’m going to try that. It would be a big benefit to certain users (particularly anime fans) if Plex supported Matroska segment linking (a.k.a. “ordered chapters”.) The clearest explanation I have found of how this works is here.
USE CASE 1
A TV series is stored with a .mkv file for each episode but the opening segment (OP) and ending segment (ED) are in separate files. Plex plays the episodes without the opening and ending segments. Stand-alone players like VLC and MPC-HC play them correctly with the OP and ED.
Note that it is not a workaround to rename the files with part numbers because there is typically a segment before the OP and after the ED in the main file.
A lot of classic anime is available only in this format.
USE CASE 2
Some blu-rays contain multiple versions of the same movie, e.g. a theatrical release and a director’s cut. While it’s possible to rip these into two giant .mkv files it is more efficient to store them as two small .mkv files plus one file with the shared segments (which is most of the movie.)