dragchute
Don’t know anything about the King Air so can’t comment. Your advise to Ang737 is appropriate, do ask the CFI what they would prefer because frankly there is no right or wrong here. He should also ask what way they want run ups done on gravel strips because he probably hasn’t been taught how to do this either. Also speak with engineers as to what they think. They are a wealth of knowledge when it comes to these things.
What I found offensive, and you may not have meant it, is the inference that all pilots that do symmetrical run ups are Cowboys and that Ang should ignore them. People can make their own judgment as to whether someone is a Cowboy or not, but don’t paint everyone with the same brush.