@Andy_Leggatt
How much data throughput do you need with that PCIe card?
Although USB 4 says it is 40Gbps. When used for PCIe over USB, the actual throughput achieved is less due to PCIe over USB overheads. Maybe 32Gbps or something like that.
Another alternative is using oculink.
Some people are looking at adding oculink connectors to the FW16.
So, if you need more data throughput, look into oculink.