asterisk users - Oct 2012 - Question on Asterisk memory management

I'm trying to add a "Talking: " field to the AMI ConfbridgeList
event so
that my conference room monitoring will work with Confbridge instead of
having to stay with MeetMe and there's something I don't understand.

When app_confbridge.c calls ast_bridge_features_set_talk_detector, it
passes a *copy* of args.conf_name.  Why make the copy?  Isn't
args.conf_name in valid memory throughout the existance of that bridge?  I
ask because the easiest way to do what I want is to change that parameter
to be &conference_bridge_user and add a "talking" field to it
(yes, I know
I then have to have the callback called unconditionally and test
TALKER_DTETECT there).  But that can't work if there's a scoping issue
with memory and the copy suggests there is, though I don't see it.