EKF3 Bitmask set to first two but VIBE data being recorded from all three

I am doing a vibration investigation and looking at IMU data in the VIBE potion of the log file. I have my IMU bitmask set to 3 which coresponds to the first two IMUs. However, within the VIBE log data is shown for IMU2 (3rd one). Is that recorded by default even though that IMU may not be used? The clip data in IMU2 is concerning but IMU0 and IMU1 show 0 clip events.

Any information is appreciated.

If you’re using a cube that sometimes happens. It’s because the individual IMUs are mounted differently so they report differently.

… and the 3rd IMU has no dampers, so it is expected to see more clipping events on that one.