Well that's a clever idea, I didn't think of stringing the whole I/O cable out the back.
That's the most flexible thing to do especially if you plan to make the box fairly sealed.
With my Zero, I still have to go in there to get the SD card.  Bravo.

My plan to finish is to house the RPi  externally perhaps in a little box
on the back so I can eventually switch in a Next Thing Co CHIP