Problems with vectored yaw stability for different motors

Hey everyone, I’m in the progress of designing a new quadplane which will utilise 4 motors. Two wing mounted motors tilt (vectored), and two fuselage (nose and tail) mounted motors assist hover.

In setting up the frame choice, it is natural to select therefore the ‘quad +’ as my motor layout in the parameters. However, as illustrated by the attached photo, my wing mounted motors and fans are different in size to the fuselage mounted ones. As these pairs rotate in the same direction, it’s unlikely the torques will be balanced.

I have designed into the ducts/nacelles angled airfoils to help balance the individual contribution of rotational momentum from each motor; however I don’t believe thrust vs torque is linear, hence this won’t work across the whole throttle range.

I don’t believe for this particular build it will be a huge problem; as it employs independent servos for vectored tilt-rotor yaw. If however I wish to use continuous tilt (i.e. one servo rotating both motors on a single joined/fixed axis), yaw stability may be more difficult.

1) Is it possible to change the motor spin direction?
2) Is it possible to use motor-inertia for yaw rather than thrust-vectoring?