If I start a new topic in source mode, and paste in code that generates a section title (e.g. using {{subst:requested move}}), I get the "Please provide a title for your discussion topic. If you click "Add topic", your topic will be added without a title" error. Might it theoretically be possible for the tool to detect whether I've included such code and not prompt me to add an unnecessary second section title?
Topic on Talk:Talk pages project/New topic/Flow
Maybe? We can always ask the devs, and they'll figure out whether it's possible. I'll get a bug number for you, and post it above.