Your challenge, should you choose to accept it, is to have the Ming Dynasty restored to the Chinese throne with a POD no earlier than Koxinga's conquest of Taiwan.
An idea I had -- in the 19th century, the Nien rebels become more organized around a charismatic leader rolleyes and ally with the Taping to topple the Qing. The Nien leader then, instead of founding a new dynasty, simply announces the restoration of the Ming Dynasty.
How about Koxinga's son invades the Philippines, establish a Ming exile government which rebuilds with the latest weapons from Europe and invades the mainland? Koxinga himself was said to have ambitions for the Philippines but died from Malaria on Taiwan before he could get to it. If his son picked up where the old man left off, they could join forces with the rebels of the Three Feudatories Revolt of 1674. Or perhaps wait until afterwards when the Qing had been weakened.