Yeah if you give it the dimensions of a standard gaylord (48x40) it tries to stack the boxes in a really strange way with smaller boxes occupying the space below larger boxes and causing some boxes to float. I wonder if additional metadata is needed such as (1) box weight (2) resistance to being crushed and (3) priority (not sure if this is relevant when shipping but it will decide which boxes don't "fit" on its own).
Neat idea though!