Feature Requests: Button text change & Attach packing slips

I currently know how to easily change the button text to just “Invoice (PDF)”, but that breaks every time there is an update to the plugin and I have to do so again. Would be great to have either a hook or setting to do so.

Also, I personally have no use for full invoice in the admin email. I do however need to print the packing slip for orders. I’m putting in the packages anyway and it displays all of the important info from the invoice. So an option to attach packing slips, or even both so we have a choice, to the admin email would be awesome.

https://wordpress.org/plugins/woocommerce-pdf-invoices-packing-slips/