Yes, it appears that due to the rotation direction of the auger it tends to give the pellets a slight push to the left which fills the left side of the pot more than the right. If you notice right after the agitator finishes it's cycle, the flame will be pretty even across the pot, but then start favoring the left side again after a while. So, no it's not the agitator that causes the left side flame, it's the way the pellets come down the chute. I use premium mode as well. The sheet metal is from Home Depot and is 26 gauge. It's not aluminum, it says "zinc coated sheet metal" on the sticker. It came in a small 18" square sheet and was cheap. You can fine tune the amount of pellet deflection by bending the left side vertical more or less to the right...like a rudder on a boat or plane. The right side of the deflector really doesn't do anything. All it takes is to deflect a small % of the pellets back to the right to get an even flame.