I originally brought up airway clearance because there's a ventilator shortage. I imagine "better out than in" is absolutely a very good rule of thumb for a condition causing the entire world to try to find ways to ramp up ventilator production. Doubly so for individuals who can't get access to a ventilator, so simply getting the phlegm and fluid out is their only real treatment option and it's one they may be wholly unaware of.