Does sticking LEGO bricks together make them easier or harder to pack away into a box of fixed volume?
If we restrict to either single or tall stacked 4x2 bricks then individual bricks pack denser. The best result we get for stacks of two bricks as they have the most spherical shape. You can find the answer in an investigation using long cylinders here. In figures 5 and 11 you see the packing density for cylinders with different aspect ratios. The density in infinitely tall vessels you find at $L/R+L/H=0$. The density is the ratio of occupied vs total space. These results are approximately also true for Lego bricks.