Hi Kevin,
Dustin Moore was really onto something important with his close contact high heats retaining insulating ideas.
As you say he proved results.
Here is a few pictures of my well used Victory model hearth that was doing the same.
Apologies. They are at the end of this post I am linking up:
What you are seeing in the lower picture IS the ash laden alumina ceramic mat insulator. The insert removed tube above was actually called, “the insulation retainer sleeve” by Ben Peterson. The pencil stuck into a screw in/out jet hole.
After experiencing the great results with this system I then personally want to have a larger diameter system with vertically set and length split wood stove brick as he tried.
He could have solved his backside of gas brick sneaking by just putting a thin layer of mat behind of them as a filler blocker.
DustinM, like many now in the last 8 years were-here, gone-now.
The hope is as a developed confident fuel-gas-maker then off onto different Life challenges.
Knock-on-wood. Here best wishes sent out his way.
Steve Unruh