When cold smoking any cheeses hard or soft, I place them directly on shelves. Putting butter, cheese, salt all together in smoker, w/ butter on top rack, soft cheeses on next, hard cheeses then salts/peppercorns/spices underneath. Never tried using Qmats for this, always did it this way before the mats came into my life.
As stated earlier cream cheese doesn't need to mellow and smoked cream cheese in a buffalo chicken dip is mighty tasty. Just put the cream cheeses in a ziplock sandwich bag and store in fridge. Butter freezes well to use as needed and store the salt/peppercorns or whatever spices your cold smoking how you normally store them.
Good luck cold smoking...