The mod is almost ready, at least in its basic, totally working form. Of course, given that this is an alternate reality, future work is probably required to make sure some future events that don't make sense won't ruin the immersion. But this is for another update.
Let me show you some screenshots of Germany if you select the 4th option, ie creating a relatively ethnic-pure Germany but excluding Prussia which loses all its post-Napoleonic conquests West of the Elbe river. By focusing on their Germanic possessions, the Habsburgs effectively liberate the Hungarians, the Bohemian-Moravians, the Ruthenians (the third
Danubian Principality), the Croats, and a small Poland that may spell trouble for everyone later. I have made it so that Austria does not give away the Italian possessions, as to keep its bases in the Mediterranean. Of course, it may have already lost them or be about to.
Looks beautiful, I think: