How to set dff value on invoice header based on customer dff value

Summary:

I have a DFF on an invoice header (RA_CUSTOMER_TRX), which is display type Checkbox. We would like this field to be checked/unchecked based on the value of another DFF on the Bill-to Customer (HZ_PERSON_PROFILES).

Ideally, I would like these values to be in synch: if the value changes on the customer it should also change on the invoice. Does anyone know how to do that?
If this is not possible, how can we make sure that the default on the invoice is the same as on the customer when the invoice is made?