Pinterest for Woocommerce should have filters (stock, sku, max, min, etc...)
I think that this plugin has a great future. I would definitly add some filters, so the XML feed can contain what you really need.
Filter by Out of Stock, Minim Price, Maximum Price, The ones that contain SKU numbers, etc... at least
Eric Caron commented
What would be great, as a short term fix, would be adding an apply_filter in FeedGenerator.php, seeding it with $products_query_args, before wc_get_products is called.
Make Your Own Molds commented
To add to this, you should be able to select what items you want available on the Pinterest shop.
agreed, will be a lot nicer and easy for websites.