In 1970's nordschleife was boycotted by racers for the lack of safety at the circuit which is understandable considering the scale of nordschleife. The run-offs were as limited as Monaco, however drivers had no problems with one while had a huge issue with the other. 1970's F1 circuit management was not in the same level seen today with a medical crew and track crew getting to a crash within seconds to assist the driver. Cars have come leaps and bounds since the plywood days.
With cars and circuit management at a level as it is now where track run-offs need not be prioritized, can f1 cars return to racing at circuits once abandoned for safety reasons?
When street circuits such as Singapore are being sanctioned why cannot Nordschleife, Mount Panorama, Imola etc. ?