New here and know little about fireplaces. I have a MBUC36 fireplace in a house bought a year ago. It doesn’t have a blower and I’m wanting to maximize heat output. My concern is with what looks like aluminum faced insulation covering the top wall of the vent area. The top vent grate is not able to be removed due to brick therefore I can’t remove the insulation. Is this supposed to be there? Is it safe? Is this ok with blowers? I’ve attached a picture.