When an order contains multiple packages where at least one package is under 5kg (eligible for MyPost B20/B30) and another package is over 5kg (requires B21/B31), attempting to print the shipment fails with an error that the weight is too high for B20/B30.

This forces users to create a partial shipment just to print labels for both parcels, which adds extra steps and increases error risk.

Expected behaviour:

Starshipit should allow mixed service codes within the same order/shipment where required, or automatically allocate the correct MyPost service per package (under 5kg -> B20/B30, over 5kg -> B21/B31) without failing the entire print.

Why this matters:

Avoids manual partial shipments

Reduces operational overhead and mistakes

Supports common packing scenarios where parcels in the same order have different weights