Hanna, I hate to say this, but...the simpler the process the better. your process had many steps along the way. I strongly believe that the simpler the better always works out better. I would reconsider how much handling is involved. When I do a FP i rub it the niht before, smoke it at 275 till probe tender, wrap and rest and done.Overhandling. Never should have drained the juices and re-wrapped. Keep it in the butcher paper with the juices when resting down. In fact, when I hold mine in the kitchen oven instead of my steam holding cabinet I get a foil pan filled 1/2 way with water, put a grate over that, then the wrapped brisket on top.
Same for any recipe, if there are 20 ingredients and as many steps, its not gonna be good.