Sometimes a mention needs total removal, particularly when someone who has lost interest in the thread says "you guys plz carry on without mentioning me". How is that possible w/your plugin? I think there could be a keyword to tell the plugin to edit a msg after submission. E.g.
yada yada %bitlbee: s/@bob@node//% to tell the plugin to search and replace a string in the final post.
also consider how cool it would be if ppl could edit a posted msg. E.g. "edit 2a s/missspelling/mispelling/" could result in deleting msg 2a and reposting it with the string replacement.