CashDtl UD Field not set when posting AR Invoice Adjustment

I have added a UD field (boolean) to the CashDtl table (Refund_c) to indicate when an AR Invoice WriteOff / Adjustment is meant for a customer refund. The UD field is available in the WriteOff customization form and has been bound to a checkbox control. All of this works. However, when the Adjustment is posted, the UD Field value is not set in the resulting CashDtl record. Is it possible to modify the posting process to include the UD Field?

You can do a BPM to set the UD field if the AR Invoice Entry checkbox is true.