Exporting a Yahoo Stores feed to Google Shopping should be simple, but the XML that you have in the catalog.xml and objinfo.xml is less than helpful, especially if you have parent and child variants.
If you want to do optimization on your Google Shopping feed in between, you’re out of luck, as there’s no way to do that natively in Yahoo.
Luckily, Feedonomics lets you easily export your Yahoo Store product data to Google Shopping, allowing you to optimize it in the middle.