PDF Invoices

I am interested in using WooCommerce PDF Invoice, but I want to make it conditional on shipping method. I only want it to send an invoice if the shipping method is bulk (i.e. b2b), and not for b2c purchases. Planning to pair it with the purchase order plug in, and the conditional shipping and payments plug in. So when the shipping method reaches the MOQ for B2B, bulk shipping becomes the only option, then making it possible for the consumer to pay using a PO. Then I would like an automatic invoice to go our for payment.