With flower you can control dose by visually seeing or weighing the amount of flower a person consumes. With cartridges, how do you control dose? Is it by timing the draw in time or just by feel? Seems like sometimes the dose (effect) is large and other times very light even with the same perceived draw in time. Or is this just one of the downsides of cartridges. Maybe the cartridge is not consistently creating vapor. Hope this question makes sense. Thanks.