Getting ready to pull the trigger on a Osburn Matrix insert and I have a few install related questions. The insert is going into a one story house and routed up an interior masonry 12x12 chimney via 6" SS liner. It's only 12' from the top of the chimney to the top of the insert. Pics of house, fireplace, etc are here. So on to the questions: Is 12-13' long enough for a decent draft? The Matix manual recommends 1' of rigid liner above the top of the chimney. Is it worth the aggravation/expense of rigid vs flexible? It's about 9' straight down, then a 30 degree slant for 1-2 feet and then down a foot to the top of the insert. I could probably do 9-10' of rigid and 3' of flex. I see lots of people referencing flue temps... have an IR thermometer, but the flue will concealed by the flush insert. I looked around a bit for flue probes but they all seem to poke right into the flue and have a dial gauge which I would not be able to see. Are there remote ones? I made a BBQ smoker that uses probe thermometers but I think they max at like 500 degrees. With a bit of cajoling I could conceivably hook up an outside air kit for the stove... what's the benefit here? You're not using your already warmed house air for combustion? Worth the trouble?