I look at Studio Script as an unwieldy yet necessary evil for starting out, but now that we have something more faithful and more authentic, it's a hurdle that we have now passed and no longer need to be limited by. Also, less bugs and chance of errors for the same reason as Troflip said. Having two languages would just be unnecessary complicating things. People skilled in one language would have trouble communicating in another, not to mention people with problems in one language wouldn't have any in the other. There are no advantages to using Studio Script over Sierra Script, other than someone being used to it. But in this case, I think it's best not to be stuck in the past and go with the more accurate and functional method. My two cents.