I have been using a 2nd hand weber chimney with my gas assist performer but i had two issues:
The grate of the chimney itself is very high in the chamber as it was designed to allow space for news print in the bottom of the chimney.
The Flames on the gas assist burner are at their hottest just above the charcoal grate of the grill itself as they were designed to be used for charcoal baskets.
When the chimney is used on a performer there is a gap between the hottest point of the flames and the coals. The coals would light faster if they were closer to the bottom of the chimney where the flame is.
My Second wish is that the chimney would fit in the kettle with a cooking grate for storage once both are cool. It would be the easiest place to store and prep the next cook. If you place the chimney the grate the lid will leave a 1-2 inch gap, which is clearly not ideal.
Since the grate in the chimney is convex (cone pointing up), i tried taking out and flipping upside down to get coals closer to flame, Since this is an older chimney with a rusty grate i wasnt able to remove it, but i was able to bend it down a bit in the desired direction. Not pretty but effective.
As i saw how easy the grate bent i had a brain storm. If i squished the chimney itself it would be an oval instead of a circle which would allow storage in the kettle with the lid on and grate in and the oval shape actually gets better coverage of the gas assist flame as the GA burner puts out two side by side flames.
Chimney can fit under or over cooking grate during storage.
The results have been great. I am seeing my coal lighting almost 5 minutes faster now that the coals are closer to the flame, and now my already easy set up is even easier:
Take of cover
Lift lid
Lift cooking grate
Stand up chimney
Dump old coals from baskets back into chimney
hit gas assist button to light
If its a quick cook ( last night i did some quick grilled chicken cutlets for chicken Caesar salad) i can get away with a half a chimney of reused coals and i don't even have to open the charcoal bin! Easiest charcoal cook ever.