This is super-interesting and thank you for doing it. I wonder if the basic assumption--"the longer you spend with an infected person, the greater the chance of getting infected yourself," is correct. I can imagine all sorts of ways that premise could be wobbly.
e.g, common sense says you'd be better off spending 24 hours in the company of someone who's highly conscientious about handwashing, not touching his face, keeping 2 meters away from you than 12 hours in the company of a normal pre-pandemic person, right?
But ceteris paribus, it seems a reasonable assumption--it's just that we haven't yet confirmed this in any kind of controlled experiment, as far as I know. (Have we?)
