Generation Nex works with the Disk Drive
I didn't see him use one in the video (but i had the volume down so perhaps he mentioned it), and when i had one, like other chip clones, it didn't even respond to the drive. Famicom carts worked fine all day long on Gen Nex machine though.
The only successful clone that's worked with the disk drives, that i've owned, is a hardware Chinese clone. It plays everything right, plus it has a composite out, so i don't have to deal with an RF connection.
I also have a Super 8 adaptor for the SNES, and it too doesn't work, plus it's 8-bit output is horrible. By far it's the worst i've seen on the clones i've had. It looks cool sitting on the SNES, but that's about it.