Although I have only been in Taiwan a short time (36 years and counting), in my view the "demands of the Chinese/Taiwanese culture" on a Taiwanese male are a continually developing matter, from the teens into adulthood. Hence, I don't think that there is a simple answer to your question . . . . . . and I don't think that the average Taiwanese person does any "personal analysis" on this aspect of his behavior.
So . . . . . there are various "events" in his life where the family/clan may demand his behavior in a certain way . . . . . and you will often see that he complies with that, even though perhaps, if he has been associating with westerners, he has frequently espoused various personal views stressing that he "makes his own decisions" and "doesn't follow the crowd."
As a practical matter, I would advise that you pay close attention to what kinds of friends he has, how he associates with them, and how he gets a sense of "personal recognition" from them, and how he reacts to various personal crises in their lives. Obviously, the same attention should be paid to his co-workers, or classmates. Observation of these aspects may give you very many important clues about his true character traits.