Specify which SKU's do not send Fulfilment Type or Stock to Amazon / Amazon FBA

Mintsoft sends stock updates to Amazon for SKUs that are active on the system. It also sends 'Fulfilment Type' to Amazon - being 'FBA' or 'MFN'. This is causing our FBA Inventory to become stranded at Amazon as Mintsoft is forcing the listing to become an MFN listing for listings that are in fact FBA listings. We added ALT SKUs to products in order to separate MFN and FBA inventory while managing a single stock record. Both the primary SKU and Alt SKU are being stranded as they are being sent with fulfilment type MFN to Amazon.