SageBrush
REJECT Fascism
One other point --I like the other parts of your post -- bravo.
As for the above, PCR based assays are not affected by antibodies, and antibody infusion does not 'speed up' antibody development.
As for being a therapeutic, it is complicated because it is most effective given early in disease ... when it is not clearly indicated. And there will never be enough to give to every infected old or fat or co-morbid person in the US.
Patients being treated with plasma products are also being treated with a host of other 'we hope this helps' therapeutics. At this stage the cause and effect cannot be teased out with any confidence, let alone certainty. It is about as anecdotal as it gets. If large scale RCT is a 10/10 on the scale of good, reproducible science to tease out causation , then plasma infusions are a 1/10.
All that said, the occasional reports of delayed viral clearing after clinical recovery are very interesting. In the treated population I presume the major risk factor for this sort of course is related to steroid use. That would match what we know from other diseases.