> What about changing the more-speech UI to allow editing the list of CCs that goes into the event as text[...]

Editing text with a keyboard and mouse is pretty easy. I am really loath to create a special UI with a bunch of checkboxes for each CC.

In this thread I've been leaving all the headers and CCs in place because the thread was _about_ those headers and CCs. Typically, however, I simply ^A and delete them before I start composing. In this reply, for example, I simply editted out the header and CCs.