From what has been said in these forums in the past, obtaining clearance from ATC to circumnavigate is not very easy in China - even for the locals! ATC is not as flexible as other parts of the world. Then, there's also the culture and saving face mentality of Captains, especially the ex military guys. I recall my ATC days when western carriers would avoid build ups whilst some Asian and Eastern European carriers simply ploughed through what must have been the tiniest of gaps!