I don't use mIRC myself so it's of no interest to me.
I don't know anyone else that has a problem with the way mIRC handles notices, and if they do they can just add a line of script. If you are not using mIRC, then just write your IRC bot and let the mIRC users decide if they like it or not. I do not mean to sound condescending, but I have also written many IRC-based clients and respect the difference between PRIVMSG and NOTICE.
