Years ago....(when flying jet freighters) there was an old examiner of airmen who stated that unless we held a NVFR rating, we were illegal if we conducted a visual circuit or a circling approach at night. He did concede that if we did an ILS on each approach then everything was ok.
I guess, technically, we cannot carry out a visual approach, for an IFR flight, by night (Jepps ATC AU-705) when within 30nms unless we hold the NVFR.
Boy, if that is the case, there has been a LOT of illegal flying by RPT guys, for yonks!!!