[Plugin: Multisite User Management] bbpress integration

Hi,sorry if it sounds lame.I can see in changelog it is mentioned:
“bbPress registration now supported.”
Can you please tell how exactly does it work?
If I have http://site.com integrated with bbpress http://site.com/forums
then suppose a user who signed up in a child site(http://child.site.com)
will have automatically a single signon/user created in bbpress?
Also in my mother site when user updates profile info/password etc then it got reflected in bbpress and viceversa.
What will happen in case of child site?Any detail on it would be highly appreciated.
Many thanks in advance.

http://ww.wp.xz.cn/extend/plugins/multisite-user-management/