Create Demurrage adjustment option for additional demurrage invoice within an official calculation

We have adjustment options for Freight and Commission, so would like to check on the possibility of having a demurrage adjustment, on top of the Agreed Amount.
This will allow us to create additional demurrage invoice.

Using other functionalities with VIP such as Other Revenue and Expenses is not feasible as this will result in different Invoice header within the stylesheet.

If Adjustment column in Operations invoices can allow Freight and Commission to have additional invoices to be created, Demurrage should have too.

The requirement will arise if initial demurrage invoice is issued and paid by Charterers, who may come back with a request for adjustment. From our end, cancelling the payment is not an option, especially when it affects previous year books.