because Encore cannot generate the 5. 1 files, there is not a good option. Your best work around, is to generate a single audio file. You are still at risk for problems putting the multiple video files on the same time line, but since the movie files are already generate, you could try that. Adding chapter markers at each video file junction is not difficult.
But a limit of playlists is the inability to use previous chapter to go to an earlier played timeline.
Edited.