I feel your pain. It seems these apps have been built by monolinguists, and the language preference/requirement you mentioned are more of an afterthought than, for example, quality/resolution preferences.

For subtitles, at least, a bilingual family needs to have two separate instances of bazaar.

Of course, that's less than ideal when you start talking about two entire video files when all you want is an additional audio stream.

I'll be checking back here hoping you'll find a solution.