You have to add a Spice server, and you should probably install UsbDk.
You can have more then one display adapter in QEMU. I disabled the other one, not the AMD RX 470. Had to disable it, because I would get the AMD reset bug on the first shutdown and second startup. Apparently my script to enable and disable doesn’t do the trick with another video adapter.
remote-viewer --spice-usbredir-auto-redirect-filter="0x03,-1,-1,-1,0|-1,-1,-1,-1,1" spice://localhost:5900
That’s the command I use in Linux, to auto attach new USB devices. It’s the command on their site.
Oh and my USB ethernet doesn’t disconnect when trying to revive my phone in Windows now, it’s using Spice.
That’ll make some stuff way easier, some USB devices change the mode they are in, and shows up as something different. If you don’t auto connect new USB devices, you have to switch to Linux, and add the “new” device.