Have a small gap in the front where my liner meets the adaptor. I can see light when I shine it down. I suppose I could fill it with furnace cement. I also have some ceramic blanket pieces. Would it be ok to stuff that in there to close the air gap? I really don’t wanna shoot cement in there unless I absolutely have to. Just a mess to deal with, especially if I ever need to pull the liner. Would the ceramic blanket piece (very small) be safe? You think smoke will leak or will the draft prevent that if I just leave it??