Drum smoker - they have a rack for charcoal mid way or so, and a rack for meat up top. Used a round grill cover for the top. Adjustable air vents at the bottom. Looks and works great.

I would continue to add supports. Even though your using 40x40(?) aluminum, extra bracing cannot hurt anything except your wallet.

Oh, and I ordered Print Bite. 200 mm. Cant wait for it. Probably a week. Also going to change the firmware to the 1.0 Dev level for the bed distortion correction, although I doubt I will need it with the PrintBite.