When using the Bulk Import process, it is possible to create part mappings using the product SKU instead of the BigCommerce ProductID.
When doing so, PartFinder will take the provided sku and lookup the Product ID for you.
Instructions
Prepare Your Data File
While preparing your Bulk Import File, you will add a new column for ProductSKU (exactly as is with no spaces and no quotation marks).
You can leave the ProductID column blank when providing the Product SKU.
The Product SKU you provide should match to the ProductCode/SKU configured on a product in BigCommerce.
Lastly, Import Your File
Simply follow the import steps for the Bulk Import Part Mappings process. PartFinder will do the rest upon import.