Well said glofish.
I would add:
A mandated standard for FMA mode annunciation. Too many Auto Throttle/Vnav mode annunciations (Boeing), consequences of mode (at least when I flew an Airbus 20 years ago)annunciations too subtle (Airbus), and throw into the pot two smaller manufactuers (Embraer and Bombardier) and that equates to too many ways to tell the crew what’s going on.
Now throw into that equation a carrier that operates two or more (or perhaps in the case of my contract employer) all four types and that becomes a flight safety hazard for pilots converting from type to type.
Oh, and make the on/off switches move in the same direction. I never cared which way the on or off function was, just make it the same across all the manufacturers.