I mostly agree but wasn’t there a pneumonia form of the Black Death that developed that could spread directly from aerosol droplets?
Direct (aerosol transmitted) very fast deaths ( less than 2 day) were not the “usual” pattern of death associated with the 1918-19 Spanish Flu, but occurred regularly and were reported all across the areas infected.
Just like the Bubonic Plague pustules and immediate death in medieval time plagues, it is as if two separate infections were spreading at the same time.