Rev 5B boards have a critical design failure.  The "belly connectors" of the TinyFPGA BX module has two parts: one is a 2x3 surface mount pin header, and the other is a 2x8 surface-mount pin header.  You can use a 2x7 pin header for that connector; but it must be offset by 100mil in order to work.

Problem is, if you look at the PCB artwork, you'll see that the 2x8 belly connector has only 14 pins.  And, it's not offset.  Which means that the whole design is junk.

There are no work-arounds for this.  I need to spin a new batch of PCBs with a proper 2x8 belly connector.  Sigh.

Upon inspection of the rest of the PCBs, though, everything else looks nice.  I'm particularly pleased with the host Pmod connector alignment.  So, there is that, at least.

Dammit, I really am getting impatient with this project, though.  I'm spending too much time waiting and burning through way too much cash.