That's a tough request. Vicidial is designed around NOT wasting the time of an agent with a dead call. Until after audio (two-ways) is confirmed (or at least suggested) by a bridged call, Vicidial won't pass a call to an agent. And it answers the call immediately.
That being said, inbound calls are different. They run straight to AGI scipts and eventually land at an agent's meetme room.
In theory it would be possible to alter the system to avoid use of ANSWER to the moment of entering the meetme room, but you'll need to do some testing to see where your roadblocks are. First try routing a call directly to an agent phone from the DID, and don't answer. If the DID agi script answers the call modify the agi script to find where and see what happens when you ... take that out.
You can test this without damaging the rest of the system by creating a new "trunkinbound" context for your new special carrier connection. Name it anything you want. Copy the exiting trunkinbound verbatim except ... change the name of the agi script to one you've copied from the original and modified. Of course, test it before you make any changes to be sure it actually works first. Such as chmod +x if you accidentally remove the executable flag from the file (happens a lot in netbeans).
You can place the new trunkinbound context in system settings (custom dialplan), so no need to edit the extensions.conf directly.
But the agi script ... that you'll have to edit directly on the hd (well, edit a copy, of course).
Happy Hunting.