> Taiwan and China being one nation is the policy of the governments of both China and Taiwan.

No one in Taiwan and not even the current government consider China/Taiwan together. When KMT fled and created the constitution they claim China. Taiwan is now stuck in limbo because the people just want to live their lives in peace and already consider themselves Taiwanese and independent. But if they change the constitution then China will consider it a formal act of independence and use it as an excuse.