Note that none of the PCIe interfaces on Strix Halo are larger than x4. The intent is to allow multiple NVMe drives and a Wi-Fi card. We also used PCIe for 5Gbit Ethernet.
Feedback: That 4x slot looks like it's closed on the end. Can we get an open-ended slot there instead so we can choose to install cards with longer interfaces? That's often a useful fallback.