Could you not install further up the stack to give fumes some time for fumes to cool down a little before hitting more delicate equipment.Can they take the heat? They seem to be made for home heating systems which don’t see more than 65° C. You will be seeing 450° C for pyrolysis and 815° C for incineration afterburner temps.
That does not sound terribly safe.I have seen chimney caps glow on metal chimneys over incinerators. And that’s on a roof top.
Is it not quite obvious that a device that uses high rates of convection to bring more O2 into a combustion chamber would act more like a molecular sprinkler than a controlled method of pyrolysis.I think the functionality of a smudge pot to do what it does requires the surface velocity to get the air to fuel mixture right for better combustion. So any modifications would limit it’s ability to burn efficiently.