I am confused on something. Is it me or do buyers not check when someone has an out of office message on? I have had this happen several times where I am out of office and someone asks me to send them a custom order. I understand they can still message us, but something should pop-up on there end that says they are unable to accept orders at this time since out of office mode is on. It should also appear in messages.
You could make a polite QR that states that you are OOO and will not be taking any orders until such and such a date.