My idea would be to cold smoke whatever I'm cooking in the PBC for about an hour or two before actually firing the coals up.
As far as I'm concerned THAT would be a big NO WAY!!! That is just WAY too risky to try and cold smoke
uncured meat for that long!
You have to remember that an enclosed smoky environment is an oxygen-deprived environment, which is the perfect breeding ground for any type of anaerobic bacteria, the worst of these being C. Botulinum.
Cold-Smoking is intended for cured meat ONLY!!! The basic rule is if it's not cured, then don't smoke it below temps of 165°
Now, if it's a really cool day, and you keep the pit in the shade, you could get by cold smoking for maybe 15 - 30 minutes TOPS! Anything longer is just too risky.
If I knew you had cold-smoked ribs or any other uncured meat for 1 - 2 hours... I wouldn't eat it. Botulism is not something to toy with.
I posted a similar comment about this over in the other thread you posted, but not as long.