I would also love to see native encryption support within mirc itself, i also suggested this a few months ago
here For now i have just written my own script (as the patch is buggin and limited), but obviously within intertwining it with other scripts there are certain things that no longer work on channels using encrypted conversation. (my reqex msg/spam filter script for example).
This limitation is the sole reason that the patch exists rather than just scripts, and is pretty much the sole reason for the suggestion of native support.