This is incorrect. The democrats in Taiwan hold that Taiwan is already independent, so seeking independence would be redundant and it’s about protecting sovereignty. The KMT is the party that views Taiwan as a part of the mainland and wants reunification, but they’re not the ruling party.

I don’t know how it works, but this has resulted in the PRC relatively supporting the KMT even though the KMT views the PRC as illegitimate. I suppose both parties would rather have Taiwan be absorbed back into the mainland, and deal with resistance afterwards.