This is what I thought I may do with the next set of shelves I make.
My plan is to make my shelves about 18 to 20 inch's wide. From Number 9, 3/4", flat stainless expanded.
I all ready have a hyd press brake that I can make a jig for to create the crease, and my bench brake would bent the front and rear lip.
My thought is that I will not have a crease from front to back only side to side. The shelves will sit on slides just like the ones you have pictured.
They will have a 3/16" stainless rod welded to the bottom of each side of the shelf. This will give it strength from front to back along with acting as another guide while going in and out.
My thoughts are why leave the door open while I am moving meat around and loose all my heat. I plan to build myself a small cart just bigger then the shelf. That way I can open the door, pull the shelf and set it on the cart, and shut the door. Do what I gotta do and return the shelf to the smoker. With out the extra weight of a clunky frame.
Some people say I am a little off, some say I am a little smoker crazy, but I figure who cares. When I smoke I want someone to check out my stuff and say WOW I never saw anything like that before. Plus the thinner the shelf the more room there is inside.
I honestly cant see a reason that stainless expanded would have any problems supporting a fair amount of weight over 18 inch's but that's just me.