Allowance of NVFR in Poland is actually fun.
Since last year they have been allowed, within controlled airspace, with the minima 5km/450m, while... SVFR night minima are 5km/500m with exception for helicopters: 3km/300m
This actually shows difference between Polish CAA [responsible for 5/450 minima] and the transportation ministry [other minima]. Anyway: it is allowed.
There're no problems in G airspace, as we have only class C ang G in Poland.