Cut a piece of hardware cloth about 5 X 16 inches.
Create pleats about every two inches by bending it and hammering flat, then clamp the crimp 1/4" down into a vise or Workmate and bend the free ends out straight. Repeat 6 or 8 times.
Roll into a tube and stuff into the smoker so that the fins hold the tube away from the smoker walls.
Tried it out today and it stays lit much better...
(I had a piece of old real heavy screen which hopefully will last a while; the light stuff we are using for SBB's might not last well.)