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Large and Small BGE
And all the toys to make me look like a Gizmo Chef.
I agree that it is an air flow problem. After just 4+ hours of L+S, plus an additional first hour of getting the BGE up to a solid 235, there is enough air restriction in the grate to slow down the temperature climb. That, plus the altitude, makes it an unreasonable amount of time. I have an XL, so I'm stuck until there's a better grate available.