If you make a little PCB with say one PCIE-4xPCIE bridge (I'm assuming those exist) you can hook it up to "just the caps". Just 12 wires and then you'd have both the existing gige and USB3 and on the board you can have 3x PCIE.... Update: looked it up: e.g. PEX8617 would provide 1 upstream one downstream to USB and Ethernet and 2 extra slots. It's called a switch, not a bridge.
Seems like it would be easier to use the Jetson Nano if you just wanted to play with PCIE as it has an M.2 connector available. I'm impressed that he got that part off without causing more damage.
