Another member that does competition cooks once commented that on his cooks he noticed the food had a better/heavier smoke flavor that he preferred when he cooked on rainy days. Something I have been interested in, but have not had time to fiddle with yet, is something that would introduce humidity into the cooker. Either a humidifier type thing before the air enters the grill or a mister that would spray a fine mist periodically, or even some combination of both. A pan of water just does not put enough humidity into the pit.
Another thing is a hybrid type system so the fire pot would run at a low setting and produce maximum smoke all of the time and a gas burner just to produce heat. I am kind of torn on this one.
Pulsating fans to produce more smoke. A setting that modulates the fan so it blows 100% for some amount of time to get the pellets red hot and then slows down and allows the pellets to smolder some to produce more smoke. This already exists on some grills but I see a move in this direction for the more economical units. It would be an easy way to produce more smoke at minimal cost for production.
I understand how natural convection works for a stick burner with no fan. I never understood why manufacturers of pellet grills, other than Fast Eddy, choose to have the same flow of heat where the chimney is so high above the grate and the fire is below. It is required for natural convection like a stick burner but when you have a fan there is absolutely no need for the chimney at the top. I see a run on top down cooking systems. They require less fuel to heat the same amount of area and due to natural convection, they have a more even temperature gradient across the grate.