Even if you had current software, ESA does not provide the functionality to dual terminate the call internally and externally. Generally it is considered a bad practice to interfere with the 911 call in any way.
What the current ESA functionality does provide is an OSN key that can buzz on a station when a 911 call is made that can alert individuals of the event. It does not provide termination of the call internally.
Given the age of the system and the release, your only option that I can see would be to go to an external Gateway to provide some advanced E911 functionality and amnagement. The only issue with that is that you are basically pointing all 911 calls down a single route list, and you may not get the failover functionality you need for overflow in the event those external gateways go down.
Given the age, none of the current solutions would have tested with Release 19.
--
Fletch
Avaya E9-1-1 Product Manager