Probably. As far as I know... any midi keyboard will work with doremi. I have Yamaha EZ-250i and it worked out of the box for me. It will accept both midi input and gamepad input which means that the official KM KOC will also work, yes. One thing to note about that though, the effector wheel will NOT work.
Btw... USB converter? The KM controller is usb interface! Plug and play
