Did this ever get implemented?
I see ISON commands going to Freenode, Undernet and irchighway.
Freenode is a failure. Not too long after mIRC added support for MONITOR, freenode inexplicably disabled its MONITOR command. They've allowed it to remain in their 005-response, illegally.
Addendum: I'm informed that Freenode corrected its 005 response indicating explicit MONITOR support, a few months ago, but it still gives implicit MONITOR support which mayormaynot be confusing to some clients.