https://en.wikipedia.org/wiki/Free_surface_effect
https://en.wikipedia.org/wiki/Metacentric_height
tl;dr version as I recall: keep holds either mostly full or mostly empty, make assymetric holds and tanks, and use baffles if you have no other options.
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