Hey all, long time lurker first time interrogator. How might I make these cheap as chips 74HC165 breakout boards work with mmjoy2?

So as far as my base level apprehension is concerned, I've managed to convert an F-22 Pro to USB using mmjoy2, mainly by carefully following pictures I've downloaded from this forum. So, I'm not that dumb, but I'm pretty dumb. I'm believe I can figure out how to daisy chain these boards together. I'm a little scared that this page seems to indicate that they actually made a typo on the board, and the input is the output, and the output is the input, but I can probably forge through that too.

What I'm mostly hung up on here is that the breakout board I've linked to takes six connections, and running a shift register on mmjoy2 or Thrustmaster/compatible takes five connections. So do I just leave one of them unconnected? Which one would that be? Here's my best effort at making a chinese room:

ser_out = serial out = SPI-MISO
SH/LD = shift/load = SPI-CS
CLK = clock = SPI-SCK
CE = clock enable = leave unsoldered
GND = ground = GND
VCC = power = VCC

Can anyone let me know if I've passed the Turing Test? Thanks.