[25 Aug 2023]

I tried a few things, such as the left/right squares facing up (see below) but I eventually settled on this design. Due to the fact that the thumb #Tetrinsic [gd0041] is 5.2mm higher than the finger ones, I've had to lift the square up to compensate. I've made the extension a dark grey so that there's contrast between the elements, but I might just leave the squares "floating" instead.