Translated text in exported files should be set to the target language.
BTW, the "Suggested topics" box here on Freshdesk doesn't seem to be working - clicking on a link does not take you to the indicated item.
For DOCX this already has been implemented. However, the source document must contain a language code to make the feature work.
Seconded. This should work always, without handling the source text first.
And yes, the bilingual files should be set accordingly: left column without checking, right column set to the target language (already suggested, but hoping that repetition will create reality...)