Since the fees change based on different payment methods a simple fee calculation can't be applied. I.e. the fee for instantEFT is different to accepting a credit card to a masterpass transaction.

This feature request is simply to return the amount paid in fees on the order page. The amount_fee can be returned as documented here. https://developers.payfast.co.za/documentation/#notify-page-itn

This image illustrates how it could look: https://shopplugins.com/wp-content/uploads/edd/2018/05/fee-in-edit-order.png