The document Cash/Cheque request should be used when the immediate payment via cash or cheque is required. This document is not in that sense supporting all types of payment. If the supplier has a credit agreement e.g. payment in 14 days it should be up to Finance to monitor the due date and settle the payment accordingly.
Change to add due date on the Cheque/Cash request will not be approved.
I have asked TANGO team to check if there was a request before to have a document for the Bank Transfer payments. Will let you know when I get their reply.