All of SW's policies apply to DING fares. When you checkin, arrive at the airport, sit on the plane, SW does not care what fare you have.
The only difference between DING fares and fully refundable fares is just that. The fully refundable part. You can always get a Ticketless travel credit, but to normally get a refund to your CC, you need to have purchases that fully refundable ticket.
Now I know that some have got a refund on other fares, but the stated policy is what I just stated.