PCIe adapters often include it, but you need to snake a cable from the card to an internal USB header to use it, while M.2 Wi ...

Overall Mini PCI-e is a fairly unloved interface, but we’ve seen the reverse of this hack before, a Mini PCI-e to USB adapter used to add a 12-axis sensor to a laptop.

Even if you’re making your own PCIe host with an FPGA and the sheer flexibility this implies, your FPGA might straight up not support bifurcation for internal ... NVMe adapters and so on.