It is possible to change the CW ID by changing it from the allstar.org dashboard.
That setting is internal to the software and loaded at boot time.
So a change requires asterisk restart.
So, the answer is no.
As @Mike said, it is a local setting. On you node pc/pi, open the rpt.conf file via asl-menu or directly by typing
sudo nano /etc/asterisk/rpt.conf
Then scroll to your node settings under [node number] and change idrecording = |i(CWid) as per your requirement. Save and restart asterisk.