This truck hardly gets driven it only has 85k on it and it started smoking slightly on start up very seldom about a year ago. Fast forward and it has increased in smoke and how often it smokes on start up and there have been times when a huge cloud of blue smoke will cover the tailgate. So it has a very slight miss to it, you wouldnt even notice if you werent feeling for it. Has no stored miss codes but the miss is there.  
Ive been really thinking hard on this and Ive seen worn valve guides smoke but this is more than that. I am starting down the road of valve guide seat coming loose in the head making the huge smoke cloud ever so often.
Im sending in a oil sample just to make sure its not lifters or cam going south but I dont see how that would make it smoke. It seems if it were cam lobe and lifters it would start rattling.  I have heard of aluminum heads having this problem but not sure how it happens. I bought this truck with 50k on it so I dont know all the history.

I would think the valve seals have probably hardened up from it sitting for long periods of time without being driven.