The way his previous way worked was create an invoice and then after it gets paid immediately send to the person's lightning address. Instead he could get an invoice from the person's lightning address, then create one of his own with the same payment hash. Once the invoice gets to him, he pays the original invoice from the lightning address and use the preimage to settle the payment to him.

I can't tell for sure but I think the power of the product was in invoicing for payees that are not constantly online, or don't have a reliable LNURL presence