I thought tip jets did not require a TR ( or mid rotor in this case ).
You are correct, none required. If you look close you will see the low rpm of the tail rotor. It is more of a live rudder to give yaw control. That way they eliminate having a big rudder in the downwash like some older co-axials and intermeshers used. For example look at the Kaman Husky , that is a huge appendage hanging out the back.
However I have seen the video of the 2 place peroxide powered prototype and it looks like are back to using vanes on the boom . The video was mainly head on shots and it was hard to see the boom , but yaw authority looked good. Probably was a calm day. Personally I hope they stick with a low thrust tail rotor that only needs to handle crosswinds.