I was taught at a tender young age by an old black gentleman who operated a very successful BBQ joint in Louisiana how to do a brisket, and it served me well for many years.
His method was to cover the meat in a large pot with water and various herbs and spices and cook in an oven at 200 degrees until it was tender, then remove and smoke at less than 250 for about 6 hours, mopping for the last hour.
He claimed that cooking under the BP made it tender and juicier.
I have barbecued many hundreds of briskets this way, for my family, friends, groups, and events, very successfully.
So, I can guarantee that precooking before smoking produces good Q.
Now I alternate between that method and the smoke first, foil next method, depending on my mood and the situation.
I get better fake burnt ends from the point by smoking first, though.