AST Tracking per Item is a paid addon for Advanced Shipment Tracking for WooCommerce. This addon makes it easy to add tracking information per item rather on per order basis.
With this addon installed you can send a SMS as soon as when tracking information is added. So you can easiely inform user which product has been shipped in case of partially shipped orders.
Why am i getting 2 SMS on Partially Shipped status’s?
AST Per Item adds tracking information and then updates order status to partially shipped, thus we receive two events. To overcome this, you will need to disable partially shipped SMS from Customer Notifications, so that only one SMS goes when tracking information is added.