just a nitpick, but the sample commands in https://github.com/sickcodes/dock-droid/blob/5a3ed6502f8fe384d462669dc83d80e317d81daf/README.md#vfio-passthrough are for virtio/usb forwarding, not vfio forwarding.
vfio forwarding would look like this:
-device vfio-pci,host=04:00.0