I think with pellet cookers you want to avoid putting in the meat until the pit comes to desired temp cause the warm up process does not really produce "clean" smoke.............
I absolutely disagree! I put meat on my pellet grill while it's still cold AND while the grill is still cold. Those pellets are very dry, you do not have to worry at all about the smoke not being a clean smoke.
Think about this: people (including me) use pellet tubes for cold smoking all the time without worrying about the smoke being clean!
The longer it takes for the outside of that meat to come to 140° the longer it has to actually absorb smoke. Starting with cold meat and a cold grill extends this time.
My favorite method is to allow at least 2 hours of cold smoke before firing up the pit. ( 4 hours for me in the cool part of the year.)
2 hours is a bit too risky, in my opinion, to cold-smoke uncured meat, unless it's cold enough outside to keep my pit temp below 50° F. Otherwise 30 minutes or so is the most I ever cold-smoke any uncured meat.
I TOTALLY agree with Tee about the probe test having the final say. I've had pork shoulders done at anywhere from 190° - 212°. However, that probe test never lies! If that probe (or bamboo skewer) goes in with little to no resistance, then you know for sure that the connective tissues have broken down. Otherwise it's not done, no matter what the thermometer says!