Firestopping/blocking is very specific in nature.
I went to a state sponsered course a week ago, and I am taking a class on Tuesday. When I am finished with the class, I will relate some info here. My eyes were opened at the State course, and I hope to have a more thorough understanding after Tuesday.
NYS is heading in the direction of having certification for the installer of firestopping. I mentioned this before, and some got upset. The reality is that there are many installations that do not meet the minimum installation requirements, and the authorities are aware of this.