I feel like the difference between symbols matters. Fonts to read with fingers are made from dots because it’s 0\1, dot or no dot, for fingers are pretty much like an eye with a very limited sight, they would have trouble discerning 6 and G, M and N. When languages like Ukrainian or Russian use similarly shaped letters i\ï or е\ё, they become confusing, as this 10% of information in dots decides what the letter means. Like a QR code, they should have enough ways of correcting the coded message even if you lose a part of image or misread it. When my eyes are tired, sans serif fonts read better than serif ones, fonts making letters like g unique by pronouncing it’s hanging loop are easier, and the less dublicate letters the better.