cardboard insert packaging

Hello,

the first PCBA shipment survived at least in part due to the extra cardboard separators, the outside box was crushed in transport.

I use thorugh-hole components that are somewhat fragile themselves, and may exert non-trivial force on the PCB when the box is crushed during transport.

Due to part optimization I might have gotten below some PCBA price threshold, and the cardboard inserts are not available when I try to place a new order.

What are the conditions for this additional packaging option?