Actually, tilting the motors “inward” for the standard quad-x layout, greatly improves yaw authority for the BiWing model in RF8. I tried 5 degrees of downthrust on the top wing and 5 degrees of upthrust on the bottom wing. This adds a yaw moment (body-frame roll) for each motor which is in the same direction as motor torque.
It looks like the Quantix has the motors tilted outward, and in that case you would need a quad-H frame for the motor torques to be in the same direction as the tilt-induced yaw (roll).