We've had unstable aircraft with computer-controlled control surfaces for over 40 years, the inherent inertia coupling tendencies will be controlled by that same philosophy.
This is not the same as aerodynamic instability. This is an inertial instability. It is caused by forces of a rotating mass overpowering the forces of an aerodynamic surface. No amount of computer sophistication can overcome this instability. The aerodynamic control surfaces must be enlarged. Further, look at any relaxed stability aircraft and you will see large control surfaces. Software alone cannot generate the large forces required to maintain control. The software needs powerful control surfaces to work with. Those do not appear to be present on the Aerion AS2.