I have a Blaze King Princess installed in a manufactured home. It has double walled black pipe from the stove to below the ceiling support and Selkirk Metalbestos through the roof. I was told once you switch to the Metalbestos you have to continue that clear up to the cap because they don't make an adapter to switch back down to something else. I have found that single wall black pipe mates easily inside the Metalbestos. Is there a major safety concern doing the above roof chimney this way? Please let me know and explain in detail as I am new to this and trying to learn. Thank you.