Most likely the screamer will usually talk in one language. let's say there is both speech recognition translated to text of the native speakers language,. make that text readout selectable to be translated into other languages so that for and readers can read what the screamer is saying in comments in their own language.

and reverse it too so that chatters could chat in their native language and appears in the streamer's native language text

It doesn't have to be a very poetic translation just enough to get by. And foreign translations should have a flag by them so that the streamer and chatter might be aware that something is lost in the auto-translation