I havent tested this with shattered balance, so there might be some weird results.
It's a bit late, but I've been playing my most recent game with Shattered Balance and this mod. The only thing I've seen is a Hellenic uprising in the Byzantine Empire, but that makes a lot of sense. I had to crush it since I'm the Byzantine Emperor, though. (Ironically, I intend to convert to Hellenic once I'm closer to forming Rome. But I'm guessing that's 125-150 years off, and I can't have the Hellenics causing problems that entire time.)
Also, unrelated, but... I'm assuming this mod will make the EU4 converter choke? I had planned on converting the game I just mentioned to EU4, but realized the extra religions from this will probably cause problems. Any ideas?