Insulation, Radiant and Vapor Barriers - Insulation question

Crawled into the crawl space just to check the area and noticed that when the Preway Fireplace was installed fifteen years ago and the multiwall chimney chase went thru the crawl space attic and thru the roof, the installer moved away the insulation in the cavity where the chase was placed and there is an area about two by three foot that has no insulation, you can see the wall board from room below. There is no evidence of any water damage, it is very dry but wondered if it might be wise to get some lose insulation and put in in that area and if so, what type would be best? I am sure the chimney does not get hot but maybe there is an insulation that does resist some heat or isn't that anything to worry about. I was just rather surpriised to find a bare area without any insulation.

My advice to you is first contact the manufacturer of the chimney and ask for possible solutions. Though it may not be hot now, it will when you insulate the area. They will have either methods or products that will allow you to insulate the area safely.