Damm, two bipolar (?) PoD
I dont know anything about the Ming/Qing thing. Columbus failing leaves me thinking other, maybe Portuguese merchant captains, maybe Bereton fishermen, maybe some other explorer looking for Cipangu, will stumble into the western hemisphere within the century, or the next at the latest.
Meanwhile the Grenadans or Spanish are full of aggresive vigor. Lacking Aztecs to conquer do they embark on some sort of crusade against Morroco, the Franks, or whatever? How does the Hapsburg empire develop, if it develops at all, lacking gold & silver from the new world?