Hello,
I'm planning on building this :
I would have save some and get a planck but I can't get the 12 columns design, every qwerty build of it I saw cut one or more alpha key to get modifiers on the left, right or both.
I came to the conclusion that to preserve the qwerty you had to add 1 column.
I suspected some firmware/chips/matrix limitation for nobody taking such an obvious way but how could it be? If we can have 4x12 or 5x15, 4x13 should be fine.
Still, maybe I am overlooking something? What do you think?