[throwaway439893]

A couple things come to mind here:

The cultivar of tomato determines how "stiff" it is, and somewhat how long until ripe. A different cultivar might result in a slight change in percentage damaged.

Heat ruining the crop? But tomatoes love heat. I know rot can set in much quicker as the tomato matures, if rot or nutrient deficiency was already an issue; for pristine 'maters, they can sit around for weeks at room temperature with no issue. Perhaps part of the issue is tomato health, and another part is ventilation / passive temperature regulation. So maybe someone could construct a cheap filler material that promotes airflow and put between the baskets.

The basket design could be altered to allow tighter packing of baskets. Currently they are circular, and so don't fit very tightly against the truck or each other. If they can be packed tighter, the baskets will help reinforce each other and prevent deflection. Square baskets may be best. There are many different designs for square woven baskets. In addition they can be made smaller which will provide more reinforcement material per pound tomato (this may increase the basket price somewhat but also reduce loss, making it a net gain).