Spring supports Unicode since like 2015 or so (except RTL). Zero-K had a mostly complete set of Chinese translation strings for a year now, too.
This is kind of still unavailable for Windows though, because the `fontconfig` library is not globally present in Windows, and so its caches are absent. Spring can generate those via `spring.exe --gen-fontconfig`, but that takes some waiting before a black screen and is therefore not default.
A reasonable improvement would be to implement a language selector in lobby settings that would generate fontconfig and restart spring when switching to chinese for the first time on a windows machine.