Cargo gets a full refund if they notice, though, so it's a considerable buff to cargo if they order preemptively and check their crates.  If something's important enough that they're sad it's missing, they'll know to request the refund.

It'd be one thing if supply_pack objects had flags for whether their crate is secure or large-wooden.  They only have "containertype", which is a string, and which does contain that information.