To what extent have you consulted the mechanical keyboard community? There is a tremendous amount of knowledge and experience about keyboard layout, electronics, software, hardware, etc. and it is not obvious to me that a community design would closely resemble what you are using. I recommend posting to https://reddit.com/r/mechanicalkeyboards, https://geekhack.com, and https://deskthority.net, and possibly reaching out directly to some of the most experienced individuals, if you have not already done so. The keyboard has been an important part of the success of at least one major laptop brand.