We want to buy a Mendota FV44i insert and my wife wants the front of it to be about 16 inches farther into our living room than our existing fireplace doors are so we can change the look of the nearby walls. This puts most of the insert outside of the existing firebox and sitting on the hearth. The insert is 23 3/4” high and our opening is 32” high. Can I put the insert here? I will frame around it with metal studs and concrete backer board, then cover that with stone. Then I’ll create a new hearth using more non-combustible material. I think 8 1/4” clearance leaves enough room for the liners to go into the old firebox and then up if that is ok to do.