I came here to request the same 🙂
At first I didn't have any languages setup and Japan news were in Japanese -- this is fine from time to time, but it takes me time to read so I looked around and found the languages option, and now it's all in English, which is great to quickly sort out what I want to read... but now I've found what I want to read I want it back in Japanese, and there doesn't seem to be an obvious way to do it.
Up until recently there was a "simplify language" icon that would re-translate the text back into the original language, but that seems gone now?
Would it be possible to have a button to toggle per article?
Thanks