Would it even speed things along? The oral argument part of SCOTUS cases takes way less time than the months of deliberation before they reach a verdict. And for the attorneys involved (many of whom are arguing the biggest and most important case of their lives, sometimes with the future of a huge issue hanging in the balance) I imagine they care a great deal about being able to clear up any questions or confusions the justices may have, even at the expense of a few more days (or even weeks) in court.