In order to use the new call forwarding SER configuration you need to populate the usr_preferences table in MySQL. Below are a few example rows which show each of the call forwarding types.

Example usr_preferences Call Forwarding Records
+------------+-------------+--------------------------------+
| username   | attribute   | value                          |
+------------+-------------+--------------------------------+
| 5025552001 | callfwd     | sip:5025554706@sip.example.com |
| 9145551451 | fwdbusy     | sip:9145550257@sip.example.com |
| 5615553320 | fwdnoanswer | sip:9545553040@sip.example.com |