My concern is scan-ability. Introducing icons introduces shapes, which in turn increase cognitive load. On a layout like this, simplicity is key in order for us

My concern is scan-ability. Introducing icons introduces shapes, which in turn increase cognitive load. On a layout like this, simplicity is key in order for users to process all the information. I did experiment with Gestalt principles (I've always wanted to say that!) and created a flat black line that rotates in 45 degrees increments for levels of difficulty. Seemed to tick off the basic vision impaired requirement - single color, no intensity changes, and works in B&W (Something all data vis is supposed to do). This has been fun!