Update outbound message title after it's gone out

I often forget to give an outbound message a title before it goes out - then I’m unable to correct my error and give it a title afterwards (meaning it shows in my list as “Untitled”).

I want to be able to change the title at any time, and I can’t see any reason to prevent this.

(My initial error would be mitigated by an unset title defaulting to the subject line, which I know is already a feature request - but even if that was introduced I’d want to be be able to change it.