I am looking into a fireplace insert (zero tolerance fireplace) but only plan to use the insert for fires a few times a week. Am concerned reading the Clydesdale manual that I would have to do a warm up fire each time to warm up the soapstone if it is cold start (wouldn't this generate a lot of creosote?). I want the fire for ambiance not as a continual heat source. Would I be better with a cast iron insert like hi-300 or jotul? Appreciate any insight as it is a big expense and I want to get it right. Also my flue is 5-1/2 inches...don't I need a minimum of 6 inches, especially for a zero clearance fireplace? Thanks in advance for any advice.