Yes they fit in the #3. They are smaller than the Smokinit racks so they fit easily in and out. They are just a little short of a full rack of ribs, but only a little hangs over and it doesn't matter because it is an open rack. In effect it's a rack on a rack. I like the convenience of using them.
I put the Bradley on a sheet pan and then the meat. I can then put oil, mustard, rub etc. on, and all the extra falls to the sheet pan. I carry the whole thing, sheet pan, Bradly and meat outside then just pick up the Bradley rack and place it on the Smokinit rack. You never need to touch the meat again after that. When you want to foil ribs for example, you simply pull out the Bradley rack and put it back on the sheet pan.Then put foil over the meat and the Bradley rack together. Put in extra liquid if you like and close up the foil. Pick up the Bradley rack and put it back on the Smokinit rack. Just do the opposite to remove the foil.