That's a damn shame, I've been waiting since last year for the mod to update. Oh well, if it can't be done, it can't be done I guess.
But I'm inclined to agree that CK2 is not great for representing the Roman Empire, or anything before the High Middle Ages (which is the vanilla game). I get annoyed from time to time when playing Byzantine/Roman Empire and that the government type is feudal, amongst other things. I do like your showcase of the "Imperial" government type, but I imagine it can be a hassle managing every county.
Also after like 100 hours of playing CK2Plus as Roman Empire (since they have Roman province kingdom tier titles, which is quite nice), I gave up completely, since the vanilla mechanics just doesn't feel right for the playthrough. I played Extended Timeline as the Roman Empire, and while it was nice, the world felt bland. So I'm quite interested in an EU4 mod, if you'll include all the mechanics you planned for CK2.
Will you be making a thread on the EU4 forum?