Supplier Portal Inquiry and Approval Workflow

Summary:

Currently, there have been several isupplier invoices that require editing due to incorrect details. At the moment, the iSupplier Portal doesn't have any approval workflow set, so the invoices are automatically submitted to Payables Module queue for validation and approval.

This also causes several issues when it comes to the Invoice Number as users cannot use the same number when the old supplier portal invoice is cancelled due to incorrect details. As per my understanding, this seems to be standard Oracle functionality and there is no workaround for the invoice number aside from defining a new one.

With this in mind, are the following options possible to impose in Supplier Portal?