For CJK languages, AOSP only includes a normal weight version of Noto Sans/Serif CJK. For me and most Chinese speaking users, this has a significant impact on UX because we often get a mixture of bold English text and regular Chinese text.
There is a magisk module (link below) adding full weight CJK font support using Variable Font technology, which only adds around 20MB to the system. I think that is acceptable to most people.
Hope this could be implemented directly in GrapheneOS so there is no need to root and rely on Magisk, thank you!
Relevant links:
https://issuetracker.google.com/issues/186033995
https://github.com/simonsmh/notocjk