airmanship :-)
........there are a few variables with regards to whether or not it's prudent to face an A/C into wind for any type of engine run ups. The wind strength would be one, if the breeze is light there would be no real advantage as to which way you face the A/C but if it where rather windy then it's good airmanship is nothing else to do all run ups into wind to keep the airflow doing it's best to keep an engine within it's temp limits, (esspecially turbo models) afterall that's the single biggest reason as to why it's taught that way (mostly ) in the first place, for efficent engine cooling under high power settings whilst stationary.
The other consideration is to point an A/C into wind in order to keep the controls surfaces from bouncing around off their stops, less damage in the long run besides at times the control column can bounce around like a miss guided crazed kid behind his dads car steering wheel causing some bruising to the hapless pilot all the while pushing & pulling at various engine controls within the cockpit:-)
At the end of the day consider those around you for any engine runups as well as the engine itself. The amount of times i've seen/heard a pilot run up an engine within very close proximity of another causing , that's airmanship.
Capt Wally:-)