I made heavy changes to the gun tooltips in the upcoming update (probably gonna be 2.1.0) so on the localizations I can't fix myself I deleted the outdated tooltips strings (so that the tooltips are working but in english instead of broken).
(There's also new content that they don't cover but that doesn't break the tooltips)

• Korean ko_kr
• Brazilian Portuguese pt_br
• Russian ru_ru
• Chinese zh_cn

I'm a Chinese user who created the Chinese localization file for this mod. I've noticed some translation issues in the latest version, specifically with the weapon tooltip display format. However, I've already fixed these issues and hope it can be of help to you.
Here is the file
zh_cn.json)

I prefer pull requests because it is a lot more convenient to add, but I'll add the file and release update with it soon. Thanks.