I believe the current method works fine.
For privmsg (i assume you mean queries) it is simply not reasonable. The difference is that the message must travel through the server itself when talking on IRC (dcc's aside), where as IM clients establish direct connections (like dcc's).
On the original topic though, better certificate management would be useful, especially with the recent scriptability use of ssl in mirc.
"Allen is having a small problem and needs help adjusting his attitude" - Flutterby