A very good read.
Can I add that with a mild 270 degree cam, there are 4 inlet valves open at any one time with their corresponding induction pulses, hence the overlapping traces.
The "overlaps" become larger as the cam timing gets wilder, hence the need for a larger 4 barrel carb to keep up with the engines' airflow demand.
The continuous flow within the carb/plenum area doesn't "yank" on the air like the sudden demand for air through an IR system.
Air has inertia and doesn't like starting or stopping.
The carbs for IR systems need to be able to supply for peak airflow at around 75 ATDC; depending on heads, CR, rod length, etc.