Re: buddypress-mu possible yet?
Where the actual work happens, in trac. Yesterday, merge work started, so I’m not sure where to put a suggestion like this right now.
If you stick it in https://trac.mu.wordpress.org/report I know it will get read by Donncha.
Also, user management is changing, so you may want to play around with wpmu 2.9.1 rc-1 a bit before filing any tickets.