Shawn
Think your spies are wrong. Take a 520 put it in the hover with ysas turned on. You can then fly a circuit with feet off the pedals as long as you do a low powered descent and a gentle pull in power at the bottom
Interesting to watch non 520 pilots faces when you do it though. I cant say I have ever experienced yaw problems, dont know about 600 or 902 perhaps they are different