Populate custom surcharge field with Square online payment surcharge?

When a client makes payment with Square via invoiceninja, it adds a line item to display the surcharge amount.

Is it possible to instead have this surcharge total populate a custom surcharge field, rather than create a line item?

Hi,

The charge needs to be added as a line item in case the invoice is paid in more than one payment.

Couldnt this just add to the existing amount in the field?

Adding a separate line item for each payment is clearer.

Using a line item also enables users to specify which taxes to apply.