toadman667,
Acejavelin's approach is a good one in certain scenarios and I must say that I have used it before, but not all that often.
As for your question at the end,
My main concern is what would happen to users currently waiting in the Hunt Group if all agents go to DND
They would immediately go to the Recall Destination since there are no agents available, but at what point in your scenario would the caller actually hit the Hunt Group; it wouldn't.
Also, keep in mind that a phone can only have 3 forwarding paths with 5 destinations per path and the second phones forwarding path would not come into play as it would follow Phone 1's forwarding path to its conclusion for that call type. I haven't played with that in years, but I believe that it still works the same as it did in the Axxess days.
Now, for my next question, what would your recall destination be? Voicemail to send it to a general mailbox?
If so then this would be my solution:
Put a DND button on all "agents" phones and when they leave they either log out or go into DND; I prefer the Logout Option myself if it is an ACD Hunt Group. Of course the Hunt Group Remove/Replace function works fine too for UCD Hunt Groups.
Set the Recall Destination to a CRA that plays a recording that says "no representatives available" and then drop into whatever mailbox you want them to leave a message in.
With this solution each person can still have their normal forwarding path to voicemail for their personal calls or DID calls and you really don't have to change much within the system as it will continue to go to the Hunt Group.
Thanks,
TE