With the Chinese version ... even when you set the OS language to English, many of the menu items remain in Chinese.
If you install additional Text-to-Speech engines (voices), when you close a TTS app, the default voice will switch to a highly annoying Chinese voice trying to speak English.
I haven't found a way to turn off that TTS engine, it always goes back to the engine when you load a TTS app.
The Chinese version is full of Chinese bloatware that you can't get rid of.
The OS looks and feels very amateuristic, compared to OnePlus.