Yikes ! No access to the Boeing FCTM ?
There are many good reasons to abide by the Boeing FCTM , most obviously that is how they want you to operate the aircraft , but just as importantly it makes it much easier to stand in front of a Board of Inquiry if you scratch the paint and you have followed SOP’s.
Much harder to defend your position if you have used your own interpretation of how to operate the aircraft.
I made it a career goal to never go there.