I am a c# developer. Please let me know if I can be of any help, if needed, for a windows GUI.
Any help will be useful. The GUI will be most probably in C++/Qt it that's ok for you.
Now other things. Since we have the expansion connector with 4 free signals there, I've decided to use these 4 pins so that they're not wasted for those who don't need expansion. I've connected one of them to the WASD block leds, second to the escape led and the third to the Fn (to the right of right shift) led.
If someone is using the expansion connector, they just don't solder the resistors and there's no problem.
Now 1 signal is unused and I'm wondering where to connect it.
One option is backspace (you could do some visual indication in the upper right-hand corner of the keyboard with it).
The second option is the ISO backslash next to left shift (if someone wants to use it as Fn).
And the third is to connect it to the rcontrol, rgui, ralt, rshift block, to replicate the Poker arrows, so that they can glow when activated.
Please tell me what you think. I don't think there's time for another poll, so just write here.