I've had an 18.5" WSM since 2004. It hasn't seen much action since I got my keg. No getting around it, if you want to cook racks flat they need to be cut. One thing you could try is shoehorning them. Place the large ends to one side just inside the water pan edge vertical. Take the small ends and fold back over to the inside of the water pan edge vertical and affix with skewers. Should be only a couple of inches and if the small end is thin enough the folded.over section will cook evenly to the thick end. On the top grate you could.sort of jam the ends in between and take the tips vertical between the handles.
