I use my kettles with the charcoal in the center often enough that i purchased 3 stainless 22.5" gbs at $120 each.
Comes complete with a drip pan. Charcoal ring is a 10 gauge ventilated 304 stainless.
Only use this configuration for thicker steaks or using a wok without the center grate. Don't even use it for wings as i prefer to cook wings etc with the stacker on.
Majority of my cooks utilizes a single or double stacker. Allows for full use of the cooking grate. Added distance to the coals prevents most if not all flare ups while still remaining very hot throughout the cooking grate area. No wasted cooking grate space when cooking wings and so forth.
Obviously i can always remove the stacker to add coals but much more convenient through the center cut out.
When more cooking space or warming rack is required. Warming rack and main cooking grate are spaced 5" apart so everything under the warming rack are easily accessible. Could have probably left more of the tines on the warming rack.
2 stackers for added distance to the coals. Uses a bit more coal but don't have to worry about the flame reaching the cooking grate.