Wow, I never thought of that. I thought that it was just that parts of the Vanilla Framework were missing or still under construction!
I guess I should have had a clue when there were NO Vanilla framework classes or any other specifics shown in the SD styling panels.
Maybe there is some advantage in CoffeeCup's Vanilla offering. This way one can add their own framework to a project by including ALL the core CSS and JS for that framework. This could be done in a similar way to what I had to do in the navbar example above.
I suppose "Vanilla" was/is just a bad choice of words for the available SD themes.
And, apparently there are more available frameworks than Foundation, Bootstrap, Materialize and Vanilla (Framework).
Here's a link to a much longer list of frameworks than the four above:
https://colorlib.com/wp/free-css3-frameworks/
Notice that the Vanilla Framework was not even mentioned in this list!