Big cook on Big Joe this weekend, using the grill as 4 cooking zones:
Deflectors up on the lower grate position, not down on the deflector ring. This gets them away from the fire and makes it easier to run higher temps, and also puts them closer to the food so you get more radiant heat off the deflector.
Main grate, outside ring is the hottest area, direct convection heat coming around the deflectors. Easily runs 100F hotter than center grate, if not more. Sweet potato and garlic.
Main grate center section, pork steaks, get more radiant heat off the deflectors while keeping drippings from falling down into fire. Ran this area around 275F. Being close to deflector, the bottom sees direct radiant heat from the deflectors so does cook quicker. It's similar to lower temp direct grilling here, just with no flames to flare up underneath.
Expander rack outside ring is hotter as the heat comes around the deflector and wraps up the dome, but is cooler than main grate as it is further up and the food around the lower layer blocks some heat. No radiant heat from deflector, this is all convection hot air, probably lower 300s in temp. Chicken leg quarters.
Expander rack center section is coolest, far away from the fire and the food on the lower layer blocks radiant heat. This is pure convection like an oven, and similar temp to the layer under it, 275, but with much less heat from below. Roasted carrots.