I have several users that complain that when they transfer a call direct to Unity from within AC the user is not placed on hold and the transfer takes several sec. to complete. In that time the caller can hear the AC user through the AC users headset.
In the AC docs it mentions that "The system administrator configures the time that it takes to transfer the call to voice-messaging system. If you want to change the time, contact your system administrator." I'm not sure where to go to make this change.