I can add overall that for the Balkans countries not yet in EU, since they are in the process of joining the EU in next 5-7 years, and surely involved in many processes, regulations, tough constitutional and law changes that will make them EU compatible etc etc. that none of these countries can even be seen let alone try to accommodate any kind of off-shore Banking services. This region is still ripe with Gov. sponsored corruption and a high level conduit of crime and drugs to Europe, so they are extra monitored by EU.
Ownership by off-shore/foreign companies of local companies is fine, but that usually is related to a business/tender/service/trade/investment that takes place within the country.
Montenegro has mostly cleaned its act on these dodgy Russian real-estate mega laundry issues they had with state help and privatizations from 2005 to 2015, so they are behaving now.
So all in all, this region can be forgotten for any off-shore stuff, unless serious millions with Gov help are laundered, but sure that's where you engage the proper criminals like KPMG, EY, etc. to help you.