Is it true that most airline pilots pick a flap setting the manual doesn't actually require?

There's no single 'correct' flap setting for every flight.

What Airbus A350 pilots actually do with the autopilot on a 14-hour flight

Learn why Airbus A350 pilots still hand-fly, how autopilot works, and why AF447 changed modern airline training forever.
Seattle Times

FAA demands that Boeing flight manuals give more detail on pilot emergency procedures

Boeing, under intensifying regulatory scrutiny after the fatal MAX crashes, has been directed by the Federal Aviation Administration to rework its flight manuals for both the 777X and MAX 10 to ...