I am doing smoke/grill by gravity feed burner.
I know what I am saying
COLD smoker can not use gravity feed.
Only if you burn fuel in flame, you burn fuel to ash and ash drops down through grate.
But if fuel burns in flame, it is not COLD smoking.
Also your fuel will form Bridge Blocking, gravity feed does not work on your chips.
There is a very simple method to make your smoke generator workable