FalconJetCaptain

Is there any documented cases of the same AOA failure happening to other aircraft other than these two?

It would be interesting to know how many times this has happened to other crews which ended successfully (other than the LionAir flight the day before the crash).

In certification, is it known whether or not Boeing failed one AOA sensor in flight testing, or was it relying on results obtained from previous variants without MCAS?

Do we know anything concrete about the experience level of the Ethiopian Copilot? Are they reporting his total time, or confusing it with his time on type (hours on the 737)? What has been reported is so low that it would suredly be one of his first flights on the Boeing.

Probably time constraints. That much redesign would be a major setback.