I'd recommend using a mask with an exhalation valve, if you can.
Excellent write-up. Though, I think it's important to note that, if unfiltered, exhalation values can potentially spread disease.
I found the last bit very compelling. David Deutsch's The Beginning of Infinity is the only place where I have seen a similar sort of anthropocentrism regarding the future discussed. Could anyone point me in the right direction to more on the topic (or keywords I should be searching for)?