In my case, you can see that it works very nicely, at least until turn 110, which is how far I tested. Factions have two regions each, except the ones who are supposed to have more, such as the Ardiei and Aedui, and the big empires of course. And small factions that are supposed to be small, stay small.
I do want it to be a bit more flexible than that though. The problem is that the current region limit system does not distinguish "may have" from "should have", so as soon as I allow a faction to have x regions it will immediately conquer that many in a predictable fashion. As I mentioned, it would probably be way easier to just use cai management to tell the AI to not desire expansion so damn much. So I possibly make a CAI component, if I can manage to understand how that works.
I also want to finish the currently unfinished parts, but I need SaveParser to check the map, and it currently doesn't work with R2 since the patch. The creator said he will update any time soon.