Engineer here
1. Since those knobs to shutdown the mcas are same as sts breaker then sts trim will also turned off. While sts is more frequent needed for landing/takeoff. Right?
2.in normal flight/aoa vane is ok, it's hard to differentiate when mcas is working? Only different while flaps already up right, or deliberately automated pilot off while getting High angle pitch. Only just 5s trimming that iterates? It will ran rare right in stall regime right, or also running on the sharp banking?
3. Its not possible to turned off just mcas instead whole sts trim system?
4. Eth302 is the b37m with aoa sensor indicator like US airlines has or cheaper that doesn't have aoa sensor indicator like lion air has.