[ncmncm]

It is one thing to feed averaged relative motion into the control system, entirely another to feed in absolute position. The flight instability in response to navigational position error is incontrovertible proof of a mistaken design. Fixing the off-by-one coding error just papers over the design error. Testing clearly failed to detect the mistake.

I would not be at all surprised to learn that commercial quads share the design mistake. I was surprised to learn that NASA professionals copied it into a Mars probe. But, notably, not into the vehicle that delivered the lander.