Interesting about that low limit. I have several hundred friends and the presence logic in the previous gen virtual worlds easily handles telling me their online status.
On the other hand, what struck me as odd though is that there is no privacy setting in domains to block sending out presence information from the domain to the identity server, or to tell the identity server (or presence server if there is one) to not disclose online status. I can see many scenarios when one or more people wish to not be found. One can do that individually by setting the “show me to no one” setting, but there ought to be a domain based or zone based privacy setting too. When going into the NeedWant, for example, one probably wants auto-privacy
About presence, I can launch interface on multiple computers as my avatar and have all those instances go to the same domain. It gets interesting. Try it.