This is almost so simple its dumb, but it would be nice to output the subs either in or with a separate blank video. The reason as newer video editors come out most support layering and some support blending. It would be nice to toss it in a layered timeline hit a blend option to null the black/color on it and have the subtitle shine through so I can do my edits with the karaoke more efficiently.
Works with rain and other effects so why not subs? Oh well just a thought.