How to Disable PO Prepayment line match, but, should be available for apply only against the PO Std

Summary:

We have a PO having 100 lines and Purchase team requested Payable Team to make 50% of PO values has advance to vendor. While doing the PO based Prepayment, they have selected 20 lines as match to extent of the Advance. After the payment of PO Prepayment, They have run GRN for Non Match PO Prepayment line and create Payable invoice against the GRN lines. After Creation of the PO related Invoice for GRN lines, they are unable to apply the PO Prepayment.

How to apply PO Prepayment with PO Match Invoices.

How to disable the PO Match Line Prepayment, they have requirement to have single PO Match instead of PO Lines.