This pataut route is more cursed than most natpop routes. Zveno is not a normal dictatorship like you would expect, instead it is something we could compare to Kim Il Sung North Korea, Stalin soviet union or nazi Germany in therms of political repression.
Basically their "gimmick" is control. Zveno believes in a technocrat government where the entire society can be manipulated for the greatest efficiency possible. The state is totalitarian, the entire economy, political scene and the civil society are under control of the state by all means. They seem to be very "progressive" in a twisted way so the bulgarian culture (and the yugoslavian ones after unification) have it's traditions purged to increase efficiency. Cities are redrawn, provinces are redraw, political positions are abolished and everythign is geared to increase the economical production as much possible.
Overral Zveno seems like like something similar to Technocracy inc but without the pseud-scientific therms.
When I finished a high succesfull pataut serbian campaign I was sure that eventually the junta would dissolve and that the state I would could one day dissolve. Zveno in another hand would probably turn into a Xi Jiping era PRC (with even less cultural freedoms) and cling indefinitively.