This is not an actual consideration in Taiwan -- the three options are "independence", "becoming a part of China" and "status quo". I think the mentioned preference for joining the US is more likely to come from a question like: "If Taiwan had to join a country, would you rather become a part of China or a part of the US?"

It isn't a thing, because its nuts outside of a “manifest destiny” wet dream

Its the kinda nutty dream likely to start a war just by mentioning it.