I would imagine as the supply chain issue is resolved this double deposit amount would go away.
We can also choose to go with your procedure. You mail the faulty card to them, and after they have received and reviewed the card they mail out the replacement if it is a valid RMA. But I prefer to opt to leave a deposit and then have them send me the replacement card. Once received I mail back the faulty card. After they have received the faulty card and it is a valid RMA they credit back the deposit I left. I've done it a few times like that and so far it has worked great!