So will the empire (Inca) discover Australia, New Zeeland, Antarctica... before the Europeans?
Will they even begin to establish some Asian trade posts, like OTL UK Hong Kong etc?
Will the norther Khanate discover Greenland and find a northern route to Europe?
Resent research suggest the Norse Greenland colony didn't die due to starvation or war with the inuits, but that it could not be sustained due to lack of trade for iron, oil, wood etc. that they could not produce themselves, and that the young and able just left and returned to Norway/Iceland in a slow process during the 14th and 15th century.
I can imagine djonks reaching the southern tip of Greenland and there spotting the ruins of farms and churches at Herjolfsnes wondering what devastated this primitive village...but they spot smoke from one small house that still keep a roof. They land and encounter a very old man and his woman who offer them seal meat and goat milk, all they have, and by the usual signs and drawings in the sand tell their story:
Here lived thousands of farmers and proud wariors for 500 years, but they all died or left. Also their own children left many years ago, and returned to their ancestral homeland in the east, but they refused to leave.
The admiral decides that this must be this Spain or Portugal that his Khan sent him to look for. The old Norse man draw for him the coastlines of Greenland, Iceland, Norway, Ireland and England in the sand and the scribe copies them carefully. The admiral feels sorry for this lonely couple and offer them to travel with him to the land their children and grand-children travelled to, but the man and the woman both shake their heads.
When the party return to their boat, the admiral order that the water storages on the ships should be refilled from the glacier-river, and that two pigs and warm clothing should be sent to the old couple before they leave.
Just a thought...