How about an earlier Sino-Soviet Split, with the USSR controlling Xingjang (as a SSR/ASSR), creating a separate Manchu puppet state (With some of Liaodong/Dalian a Kaliningrad-like entity+pro soviet border adjustments) a more USSR influenced North Korea (maybe Kim-Il-Sung asks for a more northern korean border+Vladivostok to Dalian railway) and a slightly expanded Mongolia?
Thus weaking the Mao so that they have a stalemate with the KMT (with more support from the US) at the Huai River. And maybe KMT incompetence/ corruption eventually causes more breakup (Tibet,Yunnan,Southern China,Taiwan)
So basically a China-screw.