Steve I have ben thinking about the PBC/Amazen Tube dilemma ....
Here is an experiment that may work, *IF* you are not cooking at the same time ( in other words - pre-cold smoking in the PBC, then firing up the charcoal)
Try removing the rebar, and even cracking the lid a little. We know that do ing this will allow the PBC to run hotter, because it allows more air thru-put, so...it should work for cold smoking.
The downside is when you are trying to cook AND use the smoker tube - the competition for air, and it may shoot your cooking temps too high, thus accelerating the burn rate on the Tube also...negating your attempt to smoke with - rather than burn pellets.
Let us know what you find.
Thanks!
T