Thanks in advance to anyone who can help me. I have a Homestead 8570 freestanding,new, that I am installing. The parallel/corner installation clearance shown in the manual reduces the side clearance (see pic). But my install is going in a 26 inch deep alcove (after I remove my prefab fireplace). But the alcove install picture does not mention a rear heat shield and any reduction it would bring; only "unprotected" and "NFPA 211 protected" are the choices. I have 56 inches without any major modifications-so close to unprotected, but not enough. Doesn't the heat shield count in an alcove?