Once you set the iMessage Auto Reply, then let us see iPhone Auto Calls Reply setting. From the same Do Not Disturb Setup screen, you can allow the calls from a specific group like “Favorites.” If you want complete freedom from calls on your vacation, you can select “No One.”
Calls/SMS Auto Reply app lets you add customized out of office messages that it sends automatically in response to missed calls and texts so that your clients or co-workers know what they can expect. A prompt auto-response is a great way to save relationships and trust and retain customers. You can use these messages to tell them when you will respond and what they should do in case they need urgent assistance.

I’ve had several co-workers over the years use “at my earliest convenience” and it’s always rubbed me the wrong way. It just sounds kind of dismissive like, “I don’t care when you need it, I’ll get to it when I get to it.”
As an employer one of our policies is to Call in absent days not text them in. This hasn’t worked well as employees ( especially young employees) will still text in those types of messages. It would be wonderful to have a feature in the iPhone that allows for instant text response that can be set up for certain contacts( employees). Something similar to an out of office message in email…” I am not receiving text, please call … … …. and speak to me directly”