Let's say Koxinga dies during the war with the Qing, or maybe he died of malaria as in OTL, but a few years earlier, so he never invades Taiwan. Therefore Taiwan would most likely stay Dutch, as the Qing would not have a reason to invade Taiwan.
How would a Dutch Formosa/Taiwan develop? Would the Dutch be able to keep Formosa from the Chinese and other colonial powers? And how would this impact the Netherlands and their position in Asia?