I use 4 x up-ended besser blocks arranged in a cross, so that each foot of the burner stand is on a block. I have the holes facing toward centre to aid circulation. This allows any heat buildup to dissipate and also allows me extra height to transfer to other vessels via gravity. The besser blocks get hot, but not hot enough to crack or anything. I need to work on a wind shield, I used a bunch of gas yesterday just fighting the wind.