Hi atkashinc ,
The Purchase Order updates the ATUM Purchase price field in the product. We don't update any other fields with this info.

I assume that you activated the experimental "Cost of Goods Sold" feature in WooCommerce settings -> Advanced -> Features, and it included the column shown in your previous image. Please note that experimental features are not recommended for use on production sites.
However, we do not currently plan to add support for this experimental feature.
Regarding the ATUM barcode field and suppliers' info, it's included in the 'inventory' tab. It's the same tab where you can find the GTIN and SKU fields. What do you mean?
Please note that the GTIN and the ATUM barcode fields aren't the same, and we do not plan to add any kind of synchronisation between them either.
Best Regards,
José Andrés