Not from my experience. I did extensions, both marriage and retirement, and it wasn't the same for me every time and some of those times were with the same officer.
Ex: Sometimes I would need a hand drawn map done right there and other times just a copy of a previously drawn one was good enough....
One time I was required to show my US 1040 tax return for that year..
That request was only once.
Some times they want EVERY SINGLE PAGE of my passport copied and other times just a few pages.
Without going into all the details I can honestly tell you that CM wasn't always EXACTLY the same for me.