Maybe this is possible without IRCd support, but...
mIRC would have to request that info from other users, what about not-supporting-this clients? Their users surely don't want to get CTCPs/notices/privs every time when someone enters a channel.
And look at Microsoft(R) Chat - it's most hated IRC client, because it has some weird features like that :tongue:

As for supporting this by others.. i don't want mIRC to became Microsoft 2. mIRC is not for setting it's own standards.