I hate to bring this up but... Taiwan's official name is "Republic of China" and they have written it on citizen's passport.
That's true, the ROC was founded in 1912, which is different from the PRC's founding in 1949. They both have "China" in their names, but they are different governments. And most people in Taiwan don't like being called "Chinese." In fact, the newer version of the Taiwanese passport cover (2024) has shrunk the words "Republic of China" and enlarged "Taiwan."
Taiwan and China have a complex political relationship, but the bottom line is: they have different passports, currencies, governments, and militaries. They are clearly different countries in practice. However, international recognition remains somewhat vague.
If you list Countries: Taiwan, Province of China → you're hurting Taiwanese people's feelings. If you list Countries: Taiwan → you're hurting Chinese (PRC) people's feelings.
Either way, you're hurting people's feelings. This isn't very humanizing.
Due to these political sensitivities, most major international companies do not follow ISO 3166-2 for Taiwan. Instead, they use practical approaches by simply listing it as "Taiwan" while labeling the category as "Regions" instead of "Countries." Examples include Apple, Google, and others.
In the case of Kagi News, I would suggest renaming "China | Taiwan" to just "Taiwan" and keeping the entry in the Regions category.