It works exactly the same as a stock USB-USB except that it was modified so that it can be moved inside the case between the stock cable and pcb.
So from what I see, you cut off the original USB cable, soldered that directly onto the Hasu USB-USB, and then extended the other end to the center of the case? Do you have a build log or any additional pictures of how that ended up?
No build log, but I did do a little
write-up here. The male and female USB A connectors were de-soldered and replaced with male and female JST connectors. The stock cable plugs into the converer and the converter then plugs into the PCB. I prefer writing my own keymap in TMK but Hasu does have a
web configurator that works. There were zero modifications to the board itself.