Based on the linked post, and other sources, I've updated modestly away from being worried about surface transmission or transmission outside (absent close contact to others).
Given the sheer scale of the crisis, it seems like tests involving directly 'challenging' human subjects (i.e. exposing people to the virus) would be helpful, particularly for different modes of transmission and transmission by people that are infected but asymptomatic. I'm guessing the main obstacle is that the people that would otherwise perform these tests would refuse to do anything that might directly infect anyone. That's understandable, but still seems overall tragic. Is there a better explanation? Is this kind of testing considered unnecessary for some reason?
I think that's basically it. Medical research uses an extremely strict regime for patient safety, and that sort of research is much too risky to pass muster.
That's frustrating. Do we need to build an alternative utilitarian medical tradition to be able to sensibly handle pandemics properly?
FYI, an analysis of COVID-19 superspread events is posted here. I just found it online; I was not involved with it.
Short version: The major mode of transmission (in such events, YMMV) seems to be ballistic projection of dropules while coughing, singing, or speaking loudly. Masks are recommended. Religious activities, parties, and funerals were particularly risky. Superspreading events were often upper-class, but IMHO this is probably associated with the demographics of foreign travel (as the virus is a recent import).