And if that's the minimum you're willing to accept, that's fine! I'd also be ok with evidence showing kids don't die at more than 1 per million and also don't spread the disease to others. (This implicitly values a year of in-person education at a millionth of the life of a child. Arguably this is far too low, considering that we pay thousands of dollars for a year of education and almost every statistical measure of the value of life is under $10 million. If the difference in education is worth more than $100, that would put the acceptable deaths at at least 1 per 100,000)

If you're looking for case studies... Well, Sweden is the one everyone seems to be eyeing.