i preffer dont use lost_national for general reasones.
I see rivers get craizy the ai when its moving the front and get a zone in between rivers or in a river curve. If germany dont take lowney (or something like that) german couldnt go into belgium. Similar in russiaborder, but the front moves slowly becose theres no so much province nexus.
In general it manage good the front and multifront, and the revolt garrisoning. But rivers get mad all the stuff.
I will be changing the AI settings and trying to get the AI to work "normally". If I have any success, I will tell you immediately. If you have any success, please tell me as well. Cheers