Quote from StormFXFont/FontSize aren't supported because many people use add-ons that specifically handle fonts and that would require special compatibility checks to prevent conflicts.
I do apologize, however, that they're still listed in the docs. I'm in the (slow) process of migrating and updating that info but real life takes priority. :)
Is there a way to keep it? I wanted to modify the font and fontsize of charges/stacks on some of my abilities in my actionbars (Brutal Slash and Survival Instincts). With OmniCC the cooldown text is looking neat with new font I'm using, but charges (Count) is terrible.