Well the Castine has arrived. There will be about 19 feet of pipe on it, straight up. But the installer doesn't want to do a rear exit, to a 90 then straight up. Instead he wants to come off the top and then do two 45 deg. offsets. This will look ugly and seems unnecessary. Is the Castine that fussy with draft? We had the 3CB with only abut 15' pipe with a rear exhaust and had too much draft, needed a draft damper. Please advise asap. They'll be putting in the stove soon.