I'm planning on using a rib rack to get all the ribs on my 18" WSM but I was wondering, when I foil them is it ok to put them back vertical in the rack? should I just stack them on top of each other during that 2 hour period? I've never cooked ribs before so I'm taking a serious chance and doing them for a labor day BBQ but the 3-2-1 method sounds pretty idiot-proof. I'm just worried about space issues because I plan to have a couple of tri-tips in there as well but I haven't decided how many racks of ribs to go with it.