tl;dr: ships are not going to trust the weights supplied by packers of cargo containers after mid-2016, instead the weights must be supplied to each ship by the shipping companies or approved 3rd parties in advance of loading.
It sounds like it's more a they can't correctly load without knowing the true weights of the containers, and no doubt more than a few companies that are filling them lie about the weight.
The solution is of course to put load cells and automatic tracking equipment in all cargo handling systems. One could then tell if the weight of a container changed over time, spillage, out gassing, diesel use too high, etc. With a load cell on each corner of either the truck, loader or crane one could also tell if the weight has shifted internally. Easiest solution would be to put a large qr code like symbol on every side (should be resilient to corrugation) of a container. Could be tracked visually over long distances.
It sound ridiculous, but it looks like ships were loaded based on whatever the originator claimed was the weight. The more I dive into industries, the more I realize that everything is a huge hack job. Smoke, mirrors and make believe.
tl;dr: ships are not going to trust the weights supplied by packers of cargo containers after mid-2016, instead the weights must be supplied to each ship by the shipping companies or approved 3rd parties in advance of loading.