Well, unless there’s a better way to do it, I did manage to find the file I needed to edit in order to have option text appear before the Stream list is generated.
It’s in page-frontend/page-livetreams.php, and any text and HTML formatting has to go in “echo” tags. You can see the format in the file itself.
I’ll leave this open, just in case there’s a better way to do it for the future!