I worked on similar technologies from 2007 to 2015. With tactile stimulations, using the regular alphabet, a user could read a 5 letters word under 15s after few hours of training. After 20h It was taking me <5s. The learning curve with Braille will be stiffer, I would be surprised if they can reach 100 words per second. They may start with basic common words, such as "ok" or "lol". What happens in the brain is quite interesting, you start to "see" what you feel and associate pattern with words. You don't have to recognize all the letters to get the word.

The technologie is called sensory substitution, I think it started in the 80s. Skin-reading is a funny terminology.

https://www.researchgate.net/profile/Guy_Boy/publication/266...