> That doesn't give you access to move containers in and out, the doors are very small. Cargo conversion can be done but it is neither cheap, quick or easily reversible.

True, but it would allow workers to use a dolly to easily and more efficiently load small pallets of larger items (compared to carrying them in by hand and trying to buckle them into a seat or something).

Maybe they could use also use the seat attachment points to somehow secure the cargo.