If I recall correctly Xu only challenges "pure" CMA so I guess Alan Orr is out. While I don't do Wing Chun and some don't define what Alan does as Wing Chun anymore (or perhaps ever before) I can appreciate how he (and probably his teacher) have adapted/been creative and importantly also spar. Again, my knowledge of Wing Chun begins and ends with the Ip Man movies so I'm not commenting on the "purity" of what Alan does but just appreciating how he seems to have "extracted" what he needs from the art so that he can use it in sparring and competition.
https://www.youtube.com/watch?v=ZnIVhighInU
https://www.youtube.com/watch?v=PhownwwVHdA