While certainly that has been and still case that Helo can lay smoke. IMHO it is really out of the scope of the game and for most purposes would be suicidal against any enemy with any sort of AA assets. Most "smoke" dispensers have "other" wartime uses but smoke is used in exercise situations. As for dropping a smoke pot, again an expensive asset for a mission far better covered by arty or even hand thrown smoke grenades. Try and imagine a HIP or a Slick laying 500m of smoke in front of trigger-happy troops.
Bob out