The Spanish colony of Formosa would wither slightly due to the loss of the Chinese trade due to the flow of New world metals being hampered by the edicts of Emperor Taichang, which means the Kingdom of Middag would be able to survive and thrive and split from the Spanish, however the Spanish colony of Formosa would recover shortly due to the Spanish trade with Japan.
Since the christian converts in Japan are not culturally accepted by the people of Japan, , many of the converts would go to the Formosa colony, since the Christian missions in Japan are not accepted in the Homeland and also because the Daimyos in Japan are generally against foreign religions, many would opt to Migrate, majority of the converts are from Kyushu creating areas in Formosa that are christians, the Japanese-Spanish/Portuguese trade would prosper for a long time however due to the Daimyos's harsh laws the Christian religion would hardly enter Japan and the relations would be primarily based on trade due to the toughness of the Japanese Daimyos.
By 1630, the natives of Formosa under Spanish rule would have been converted to Christianity completely in the Catholic religion completely abandoning their marriage taboos, the tribes that would benefit the christianization by the Spanish would be the Atayal and the Siraya who would increase in population gradually.