Yo gums, whilst your alternative approach would be feasible, Pprune analysis is irrelevant in judging and approving the Max to fly again - just satisfying our need to understand or learn, each of us differently.
‘We’ don’t certificate aircraft; we trust someone else to do that, which in this instance that trust has been strained. It is doubtful that self-Pprune assessment would improve that trust because trust depends on more than data, it involves process, time, and unquantifiable human attributes of ability, reliability, integrity, etc.
FDR accident analysis is an evaluation of what occurred, judged against what was expected for an aircraft with known, ‘certificated’ characteristics.
Flight test analysis requires detailed and a larger range of data, it involves judgement of something new against requirements.
The certification arguments for MCAS were flawed, but the principles were proven in flight test, certification, and subsequently commercial operations. MCAS worked as designed; however history shows that the supporting design was not fail safe, nor in that sense, were the interpretations, judgements, and approvals in the regulatory process; both systemic failures.
The basic unaided Max does not meet requirements, but arguably the aircraft can be flown without MCAS as an abnormal operation - not for commercial use excepting continued safe flight and landing. If this was not so then the ‘bent tin and rivets’ would be visible by now.
What appears to be of continuing concern is the transition from normal MCAS aided flight to abnormal unaided flight. Again, arguably, this is does not involve inhibiting MCAS - automatic fail safe, but the issues associated with the cause of the shutdown and crew interaction - managing consequences, distractions, ambiguities. These are uniquely certification judgements, and not quantifiable with data.
There may also be other issues not considered in the original certification - ‘because it’s the same as the NG’, which the Max is not - the realisation and acceptance of this by the ‘trusting’ authorities - let’s look again.
The aerodynamic differences could challenge the assumptions made for managing trim runaway, or adverse MCAS influence or manual trim use during upset conditions - speculation, but consider issues arising from recent NG accidents.
Then there is training, required experience, same type rating, etc, just as significant as aerodynamic design and system reliability.
Happy Christmas; but don’t expect any Max test data in your stocking.