What the article talks about is 2-phase cargoes, cargoes which are expected to behave as solids but could turn to liquid under certain unpredictable conditions.

Accounting for these scenarios might involve upsetting the economics of said cargo.

Edge cases basically :D

Think of box with a grid inside it

Once the cargo is filled

The grid lines are raised (hydraulics) which compartmentize the whole cargo into blocks.

Invidual compartment will not have enough mass of material inside it to break the dividers if designed properly.

It's probably cheaper to just have baffles and vacuum the cargo out.

The status quo is cheaper still