I would say it depends on what you’re going for. If you’re looking for classic Texas, butcher paper is traditional. Just spritz the paper well, optionally add a splat of tallow and wrap very tight. I’ve also had great results with foil boats on the drum. Just be cautious what if anything you add as a braising liquid: it’s easy to way over-salt at this point, after all the meat should be well seasoned to start with, shouldn’t need any added strange flavors. As others have said, there’s a risk braising (pans or foil) turning your brisket to stew; personally I’d avoid with Prime or Wagu where tenderness is not at issue.
Hope this helps!