Availability For Variable Product Only

I have the feed set to “Variable product only”, so it’s only showing the main product for variable products. But [alg_product_stock_availability] is returning empty. Does this shortcode only check the main product? How can I have it check if any variable products are available and return, “in stock”, otherwise if all variable products are not available, return “out of stock”?

Just discovered this plugin, it’s very good, thank you.