You also have to keep in mind that the people with a connection to the Mainland are far fewer than those who support the KMT. Only ~1 million people arrived from China in the 1940s, meeting the ~6 million Taiwanese already there.

Polling shows that already KMT supporters are evenly divided between support for formal independence and unification: https://jamestown.org/program/taiwan-opinion-polling-on-unification-with-china/

Younger generations are overwhelmingly pro-independence and overwhelmingly identify as Taiwanese. The legacy at the top of state and society of discrimination in favour of Mainlanders and Chinese nationalists during KMT times hides how big the shift is.