Oh, interesting. Looking at it I see the potential headache if we want to plug multiple devices. But for for a single one it seems that it's enough to pick the first of the multiple of signals that you mentioned, that are exposed by the main board, and plug them directly to the PCI port (so REQ0#/GNT0#/IDSEL0, map INTs 1:1, ...). I hope I'm right 🤞.