Just a quick update...
The 30" MaterBuilt electric smoker worked great for exactly why I wanted it. For the Band Cookout I used it to bake 4 trays of Mac & Cheese and it worked perfectly!
The "Lasagna" size/style of foil trays fit into the shelves of this smoker perfectly leaving enough space in the front and back to allow the heat to flow through the unit properly. So if you're looking for an overflow cooker for doing this sort of thing, or to keep food hot until serving time, this is a great option!