I thought the only time you didn't have to produce it was when you weren't carrying. In any case what does not producing it buy you?
I just don't understand why you wouldn't show it, after all if they run your DL they will know anyway. I fully intend to show my CHL if I ever get stopped, why make trouble for yourself if you don't need to?
I guess it is a personal choice, and I choose to be as helpful to an LEO as I can be.
