Since I do not own a MES nor it's cold smoker, my comments can only be generated from what I am reading here, but my thoughts are that if the MES cold smoker has a heating element, then that alone is the flaw in it's design, which will never allow you to bring the chamber's temp down to a reasonable true cold smoke temp that would be ok for cheese, butter, etc. This is because you will be battling both the heat generated from the heating element as well as the hot coals of the chips or pellets. If one is to live with this, then the only recourse is to separate the cold smoker from the MES chamber as far as possible which has been suggested. Even then, odds are you will only be able to use it on some of the coldest days. Maybe, maybe not. It just depends on what one is trying to cold smoke. I look at cheese and butter as being cold smoking products.
Whereas with a AMNPS or AMNTS device, the only heat generated is from the hot coals of pellets. Using one of these devices in the MES cold smoker, you might still want to separate the smoker from the chamber but probably would not need to be 3 feet. For sure, you would probably have far more days to pick from when wanting to smoke some yummy buttah'.
Just my thoughts.......back to bed I go counting the rain drops hitting my skylight.