>Rather than setting data- fields, why not just keep it in the backbone model and use events to trigger the right model?

For now, I need this data-attribute to find appropriate item to remove (See [translations_editor.js#L123](https://github.com/edx/edx-platform/blob/alex/multiple_transcripts_editor/cms/static/js/views/video/translations_editor.js#L123)). Notice, that whole editor works just with 1 model. 
I'll remove those data-attributes during refactoring.