Some good information here but 1) Diamond Princess had 18% infected, half of which were asymptomatic, not 18% asymptomatic, 2) mathematical models certainly do not lead to "reliable" projections of the pandemic. Cite any one that has. 3) Asymptomatic and presymptomatic are different. Asymptomatics never develop symptoms. Presymptomatics will develop them within days. Both might transmit, but you need to be clear there's a difference. 4) if there is not yet herd immunity the default option is not to continue extreme distancing for the entire population but to protect vulnerable groups, especially if the infection mortality rate is shown to be quite low due to large mild and asymptomatic cases, such as was found in Germany, Italy, and Iceland.