At the High School I went to in England we used to play a Blind School every year home and away. Gosh, that has to be 50 years ago now.

The board in the picture is almost exactly the same as what they used, except the edges around the 64 squares where deeper, which I imagine that was to avoid them by accident knocking off a piece. Their hands used to fly around the top of the pieces and squares at a high speed so they can touch and feel each square at speed. So, I would imagine the pins need to be deep enough and solid enough to avoid knocking over and falling across a table or floor.

They also used to often sit and have it on their lap with their fingers working away across the board.

I think it would be good to also build in a timer that if they want it tells them maybe every 30 seconds the time elapsed for example if they are playing the computer.