I think a confederation of the rhine category would be cool. I also think it would be cool to seperate formables by like nationalism status for example forming canada as a canadian province like the hudson bay company, versus forming it as the British. You could add a rule that for the nationalism category you must have full autonomy before the run can be considered complete. So the confederation of the rhine could have seperate categories for whether a foreign power such as france forms them or whether a german state forms them.

The idea behind formables is that you the player play as the country that is formed. Though, if there were a high enough demand for these separate categories and they're fun to run, they could be made. IF you're talking about no release and play, where you start as a GP and release the country that forms said country, that is a possibility to be made