Thanks, very, very cool, but testing a passive riser. A rig like that is for debugging actual expansion cards I think?
Kicking around the notion for a TAM riser with a row of shorting block headers that'll look a little like that crazy porcupine.
Wanna give a try at powering the card stack from USB-C so there's enough of its anemic power/cooling budget left on the board to power the requisite G3 L2 Cache Slot Accelerator.
PTO for a couple of tiny cooling (encourage air to move up through the maze) fans in that kluge might be a good idea too. I just cannot believe they removed the SkinnyBack's fan when they designed the FatBack . . . Apple.
Thought from anyone on that crazy AuxPSU contraption would be much appreciated.
Beginning to ask around; you wouldn't be doing anything in the realm of FPGA would you? Need some advice on that front. Anybody?