> The major risk is the virus we think is safe is not 100% safe.

IANAD, but IMHO you cannot just sequence the virus in asymptomatic people - you have to sequence a randomized, sizable % of the whole positive population, including mild or severe cases, and the dead too. Only then you'll be able to "paint a picture" of the different strains' effects on humans and slap some confidence data to each identified strain. Your idea definitely looks promising though.