We tend to discuss Japan or China becoming Christian, but Hideyoshi made an interesting point to the Spanish when discussing his crackdown on missionaries.
"If either religious or secular Japanese proceeded to your kingdoms and preached the law of Shinto therein, disquieting and disturbing the public peace and tranquility thereby, would you, as lord of the soil, be pleased thereat? Certainly not; and therefore by this you can judge what I have done." In OTL there was, of course, Chinoserie, but this was restricted to artistic tastes.
So, how does early modern Europe respond to East Asian Buddhist monks, Chinese scholars, etc. floating around? My guess is that even with a more assertive Ming or Qing, you won't see widespread conversion, but I could certainly see Confucianism influencing European thinkers.*
*And centuries later, movie studios in Fusang will make movies about the Outlaws of the Water Margin, a plucky band of rebels and bandits in British North America who need a Confucian scholar to lead them to victory over the English.