I have a suspicion that given the failure mode includes the sides "balooning" out, if you built a tower that is 4 x 4 studs using 2 x 4 bricks with a 90 degree rotation between each pair in your 3 high stack, the pressure will be more than double the 4 x 2 stack alone.
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Overhead, the Albatross hangs motionless upon the air,
And deep beneath the rolling waves,
In labyrinths of Coral Caves,
The Echo of a distant time
Comes willowing across the sand;
And everthing is Green and Submarine
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