It increases DPS to weave off GCD consumables and abilities during Firestarter/thundercloud procs or the small extra time you get casting a hastened fire III or bliz III when changing stances. It's not much, almost not even enough to notice, but for the number crunches, its correct to do it that way. The only exception is popping a int potion to increase the damage of all your next fires. So yea, you're correct.