You might want to consider alternate technological approaches. Have you considered using an IMU to deadreckon the route and detect rests and falls? I think this would be an perfect application. Then you wouldn’t need the rfid tape. You could also probably use an existing 3rd party hardware. I think developing the hardware and managing its production will kill you in the end. Plus, who wants yet another doodad to buy and wear.
Another possible method is to use computer vision and video to capture the climbers motion.
Another possible method is to use computer vision and video to capture the climbers motion.