I’m surprised there aren’t lower tech ways of detecting thin branches besides doing real-time analysis of the live video feed. Like some kind of primitive proximity detection using radar to augment the image based approach, and if there is any doubt, taking quick evasive maneuvers.
High res radar seems pretty energy intensive and doesn't scale down to typical drone size (especially considering the new registration requirements for over 250g drones). Dry branches have low radar signature but are still fully capable of catching props. Low torque motors paired with large props optimized for flight time and for smooth cinematic flight (remember, it's foremost a flying camera) aren't capable of super-fast braking either.