Way back, the guys who had trouble with crank arms coming loose most often greased the tapers liberally. The Official Campagnolo mechanics of the day suggested very very little grease on the spindle tapers, basically apply it an then attempt to remove it with your bare fingers, the thin film left was enough. with the arm dry.

I have never had a crank arm come loose. A few seen coming in for repair way back, almost all of those required new arms due to deformation of the port or in only two cases, cracks radiating away from the spindle port, on those the arms were very well creased...

45nm comes to mind as a torque level. Don't ask me if I use one.