I don't personally think branching is necessary or even the most intuitive solution. Just have the damned subtitles burned into the picture like they're supposed to be! If foreign languages are included in your releases, let those subtitle translations be in the subtitle track, and let them be in the matte. It's as simple as that. Everybody wins.
And if I was one of those foreign viewers, I'd prefer the ORIGINAL English crawl to be there, and let the translation for it be in the subtitle track as well.