What happens:

1. Go to the English Wikipedia. Open a page in the visual editor.
2. Send feedback. Don't include a subject.
3. See the feedback, with no ==Section heading==, appended to the end of the page.

Now try it at a Flow board:

1. Go to mediawiki.org. Open a page iin the visual editor.
2. Send feedback. Don't include a subject.
3. See the error message: "Error: Edit failed".

Either we need to require a subject heading, or we need to fill one in if it's submitted with a blank line. Feedback centralization for the visual editor probably shouldn't proceed until this is addressed.