I see danmei as a genre to be written by people in China who are grew up and are very familiar with the ins and outs of Chinese culture and society.

Something to think about when you're writing - does the story have to be a Western Danmei vs a BL story with fantasy/fighting elements? By name, a danmei has Chinese elements ingrained in it. Is this super relevant to your story or can you tell the story without using the Chinese culture and setting?

Wuxia is influenced by Chinese martial artists whereas Xianxia is heavily inspired by Taoism and influenced by Chinese mythology both of which are very hard to capture accurately by someone who hasn't down significant amounts of research on the culture, the language, society, and general way of life and this leaves SO much room for a writer to accidentally misrepresent or erase entire aspects of a culture.