Thanks, I'll check it out.Pops you might be able to spray some high temp sealant onto that Fiberfrax to keep it from turning into powder. There is a thick goopy stuff called "Ocean" coating, very heat-resistant. It is used to seal firewalls IIRC.
I believe ACS has it. You could thin that down and spray it, or even roll it on the cabin side of the Fiberfrax???