Might be worth getting in touch with the folks who are making this, they might already have solutions for text/iconic mixed environments and this would be good for them as well as this use case of yours needs a really robust solution (also educational use is the best place to get stuff developed with all those massively imaginative students around 
).
(not affiliated BTW, just remember thinking it was good idea for screens in general to have touch feedback as well as the Braille use)