Hmm. I think this board (and all of the x299 boards that achieve 4.4ghz) needs a better cooling solution to really test it. Either LN2 (which would likely be a nightmare to use as an objective test) or maybe delidded with a custom water loop. Delidding is fairly effective on x299 (replacing the TIM with something decent).*
Then again, this article serves as a good example of the woes of overclocking a 10 core cpu. The motherboard isn't going to change the results much for most users because heat is usually the first problem.
*Why Intel decided to skimp on TIM with their $1000 CPUs, I have no idea. But I really don't think penny pinching is a suitable explanation.