Helikopter Sevice regularly checks the approved Engineers in the sim, also some authorities will allow engineering ground runs if the Aircraft is tied down.
Don't forget that Engineers in the fixed wing world are allowed to run and Taxi aircraft. Granted a 747 won't suffer from Ground resonance, but then again how often do helicopters these days. Proper training could sort the issue as is done in Norway.
Sorry drifted off thread slightly there.