A flying wing pusher airplane design

[David Lewis]

I doubt these models have abandoned natural stability. They likely still have a normal positive stability margin.

That's correct. They possess inherent stability. If you turn off the artificial stability, unlike a quadcopter, they will keep on flying (albeit requiring more pilot skill and attention).

The most common digital stability augmentation system is the Spektrum AS3X (Automatic Stability 3-Axis), which has rate gyros and a heading hold gyro. It also has a separate function called SAFE (Sensor Assisted Flight Envelope) protection. This adds self-leveling and roll & pitch limiting.