I seem to recall there was some playing around with Suzumiya-style Anachronic Order in earlier MoR chapters, but it was pretty self-contained and easy to follow. Plus there's some just downright confusing parts- chapter opening quotes that are never referenced again, Aftermaths that don't seem to have anything to do with the previous chapter, stuff like that.

And there's definitely some real potential for an omake chapter of Bad Ends: Harry accidentally destroying Dumbledore's ability to cast the Patronus Charm, Harry insulting his mother to Snape just a little more, Harry saying the wrong thing to Lucius in King's Cross, Harry realizing aloud to Quirrel what the ritual to summon Death really was...

Harry successfully transfiguring nanotech.