When I'm cold smoking with the AMNPS in my Masterbuilt 44 inch, I see smoke leaking out through the door joint. That's with no heat and every vent on it wide open, including the new 6 inch vent I recently installed. When I'm hot smoking, it's worse.
I decided I'm smarter than a smoker, so I fixed it. I smeared a thin film of lard on the door jamb of the cabinet and then applied a bead of 500* rated silicone caulk to the door where it meets the jamb. I shut the door, latched it and left it sit to cure overnight.
The door doesn't leak anymore.