^^ Yes, plenty of accidents have been avoided due to systems knowledge.
A four hour oral? and...
The checkairmen always made it fun as well. It was always "hey, you're doing great, lets load it up a little more".
The idea behind "doing great" is that you're going to smoothly sail to the end of the ticket risk event
because you're doing great. The last thing I want to hear... "Hey, you're SE downwind for the RNAV RW 11 after the fire; doing so great, I think I'll toss in a flight control failure on top, and drop the weather down. You guys can handle it."
And to be told "you don't need to know that" is BS. I can't tell you the number of times I have been able to reset the right system and get home rather than have to deal with a contract MX guy
I can't disagree more. Are you being paid for A&P duties now? And are you authorized to do that kind of thing airborne? We're not, and for good reason.
Sorry, the last thing we need are more systems wizards and professional flight engineers teaching ground school.