I have a stone wood burning fireplace with an arched opening that’s 33” wide and 29” high at the center of the arch. The chimney is 30’ high and the terra cotta tiled flue has an interior dimension of 7” x 11”. We recently had a level 2 inspection performed that revealed gaps in the tile, and a wood burning insert was recommended. We’re hoping to continue using the open fireplace, but have been told that we’d have to insert an insulated liner and reduce the size of the opening. We were also told that the only way to reduce the opening is to add stone or other masonry materials at the opening, which would look terrible. Various online websites suggest that cast iron plates would also work. Is that true and are there other solutions?