That is a cool device. I've thought of fabricating one. We'll see.
I see you used foil ... and I understand why. But, is it totally necessary?
I didn't use any on my first and only attempt last December using my mini UDS.
I kept an eye on the smoker temperature with my ET-732. Got up just above 100° at times. No problem.
Next time, I want to slice the chunks thinner (in half) to get more smoke exposure.
Please don't view this as a hi-jack. I just want to contribute. Thanks.