Hi, hoping someone can help resolve a question I've had for a while. I recently installed a 316Ti liner in my chimney for my wood stove. The stove sits in front of the fireplace and the piping runs through the damper plate opening and up the length of the chimney, about 20 feet. At the top I have a plate covering the flue with a cap on top . I packed some unfaced fiberglass insulation around the liner just under the plate at the top of the chimney. I was told by a local chimney sweep that this was acceptable. However, I have read elsewhere online that mineral wool or other such insulation should be used near the pipe. Anyone have experience with this? Thanks for any help.