How to Update Only Item Structures Without Unassigning OperationMaterials in WorkDefinition

Summary:

When updating Item Structures, you typically set a disable date on the existing structure details (UPDATE) and create new structure records (CREATE) in order to specify, "Use this BOM from this date."

However, since OperationMaterials in the WorkDefinition refer to the existing structure detail records (those being updated), they end up referencing the now-disabled records, causing the assignments to be removed.

Therefore, it's generally accepted practice to also run the WorkDefinition import together.

That said, there are cases where only DFF information is being updated in the structure details, while the item itself remains the same.

In such cases, where you only want to update the BOM, is there a way to prevent the OperationMaterials assignments in the WorkDefinition from being unassigned?