When you kill that MCAS or it has it's once limited "correction" - you are flying an aircraft that can no longer meet the certification requirements that it is approved for!
So say again - it no longer can meet certification requirements in certain flight modes/areas.
This is true but only in one very specific flight regime at very high angles of attack, near the critical angle, which during a lifetime of line flying a crew is unlikely to ever get near.
You try make it sound like the aircraft is uncontrollable if the trim disconnects are selected off and MCAS is isolated. Nothing could be further from the truth.
So how often do you fly outside certification limits? and how much training did you receive to do that? and was it on an Ipad?
With the trim disconnects off you will not be flying outside of limits, only at VERY high AoA and WTF are you doing flying there?
If I remove the interior rear vision mirror from my car it is no longer equipped "as certified" by Australian Design Rules (ADR) and would not be roadworthy, technically. Is it still safe to drive, of course it is.