You know I cooked a 11 lb packer last Sat pit running at 275-300. three hrs in the smoke neked, removed from the pit I cut apart 3 brown bags and tightly wrapped the brisket and back on tho the pit for two more hrs. probed like butta. removed and rested on the counter top until the It had dropped into the 150's( the thermo was reading 206) About two Hrs. It was jiggly.
The reason you had bad luck with the brown paper is two fold; The meat was loosely wrapped and there was not enough paper you can get by with two layers but you have to wrap it tight. I know you thinking that it is the paper but it aint, and for the record AF wraps 3 layers of Butcher paper on his. I know a chuck roll aint brisket I've cooked a bunch of them and sometimes can be a little tougher nut to crack But I never had a 4 LB chunk of cow ever go that long. If you noticed I never checked the temp on the meat so I couldn't tell you what the IT was when I wrapped it. I feel that 3 hrs was plenty but I cook on a Stick burner too.
I'm a Proxy Vegetarian> Cows eat grass & I eat cows.