On the DC controller and expander, only 6 (in fact, technically only 5) wires are used out of the 10-pin cable. The Eagle design files of all versions are in github, maybe you were looking at the wrong github, but the correct link is here:
I’ve attached two images showing the 10-pin connector on the controller, and also on the expander, so you can figure out exactly which pins are used, and the ordering of pins. When I say ‘technically 5’ I mean the DCG (DC ground return) occupies 2 of the pins, so technically if you are short of wires you can just use either one of them.
Please note that in contract to expander 2.x, expander 3.0 uses I2C, so there is no DAT, CLK, LAT, NOE etc., instead, it has SDA, SCL.