Each smoker is unique and has hotter spots in different places. Trial and error learning will come with experience. I’d put swap them around periodically until you learn where your spots are located.
I ordered the 590 with the competition cart and it came with the original cart as well. Seems like it would make a handy cart for something if it had a top shelf and is useless without it.
Have any of you built a top shelf or modified this cart?