After several rounds of beta testing, downsizing the symbols to the top most popularly used symbols. Refining the position of the glyphs within the keyboard... here's what I've got to offer.
I used Open Source Calc to plot the pattern. I formatted all the cells within the pattern to be center-aligned, and made every other row have a yellow background fill. The cable stitches are made up of two letters as you can see in the bottom chart. What do you think?