If you add or remove a SKU from an existing order (the change order process) and the SKU has a multiplier unit different from 1, the unit multiplier is not considered for calculating the new order value.

• Add or remove the sku with a unit multiplier different from 1 to an existing order. You can check out more about the process here: Changing items from a completed order.
• Notice that the unit multiplier is not considered when calculating the SKU value and the total order value.

The change order can be done via API "Register change on order", and the store is responsible for entering the values correctly, according to value and unit multiplier.