Just released, the new WPSSO Google Merchant Feed add-on retrieves product information from WPSSO Core Premium and provides maintenance free XML feeds for each WordPress language (aka locale).
There are no add-on settings to configure — the WPSSO Google Merchant Feed add-on automatically retrieves all product information in the language (aka locale) requested.
A supported e-commerce plugin, like WooCommerce or Easy Digital Downloads, is suggested but not required — the WPSSO Google Merchant Feed add-on can also retrieve custom product information entered in the WordPress editor Document SSO metabox. WooCommerce variations and additional WooCommerce product attributes are fully supported.