If you split the payment into multiple lines and designate the invoice numbers, Manager will show the separate amounts, because that is the way you entered them. If you leave the invoice number blank and let Manager distribute the payment automatically to the oldest unpaid invoices first, only one line will show, again because that is the way you entered it.
But I wonder why you care what a supplier statement shows. Businesses do not normally send statements to their suppliers. The real purpose of a supplier statement is for internal review. For that use, the separate lines would be more helpful in verifying that each purchase invoice has been paid, by matching debit amounts to credit amounts.