Greetings from Kansas USA!
First off I want to say that this is an amazing project. I'm a rookie in the RC world, although I've been doing electronic engineering for 40 years plus. I am intrigued with the stick force feedback capability of this system. I fly multi-rotors and was wondering how one could get feedback from a system that doesn't use mechanical servos. Could the current draw of the motors be monitored and translated into data that controls feedback to the sticks? Or, the gyro and accel. data? Motor current draw would seem to reflect how hard the aircraft is working to fly. Just a thought.

If the vehicle is not a plane or heli, it still can get feedback from the sensor module through Gyros or Accelerometers. I haven't really explored the MultiRotor feedback yet but it shouldn't be more than few alterations in the code and a new setup menu on the system.