As a point of information, why do you want to use an aerobatic airfoil for a horizontal or vertical tail?
Great question. And I could be very well proven mistaken, but here is my thinking.
1. At ultralight speeds (even with there being no speed limit for Part 103 gliders) there may not be a huge aerodynamic advantage to using any airfoil at all as opposed to even a flat plane.
2. Weight is a very big factor on an ultralight and structurally, an airfoil with a forward max thickness could offer a weight advantage by allowing for a smaller d-box.
3. A thicker selection than just a flat plate could allow for lighter weight by taking advantage of thickness for mechanical efficiency (thicker airfoils are more efficient mechanically).
4. The difference between the ideal and a mediocre airfoil seems to be less than an average airfoil and a flat plane (as is common in many ultralights).
5. The straight run aft of max thickness may allow for VERY simple rib construction (simplicity is a major focus with this design).
So my logic is that an airfoil would be better than no airfoil and that this "aerobatic airfoil" offers a more efficient structure and simpler construction than others that probably offer only marginal improvements at best.
But... As a counterpoint: that's an awful lot of thinking when you could just glue a few flat sticks together.