But remember what Alan says about Fauci: he is only considering the medical aspect. You are going to need some experts on the post office to opine on how likely your ballot is to reach its destination, and some election experts to opine on how likely it is your vote will be counted if it gets there.
The USPS has already opined on this and the opinion is not in favor of mail in voting.
There are two types of mail for letters, first class and marketing class, and under normal circumstances it takes 2 to 3 days and 4 to 7 days for first and marketing class to reach its destination, respectively. Now, since it would be considered voter suppression if you required people to buy their own stamp and/or forcing people to pay to vote (which will be viewed as a racial issue by the Dems), all mail in ballots will come with a pre-stamped envelopes. It is almost certainly the case the states will be using marketing class. Marketing class is almost half the price of first class and will save a lot of money (I know from my own business), and since government always takes the cheapest way out I doubt this will be different. Marketing class postage also can only be printed on the envelope (they do not make marketing class stamps), which are almost never post marked. This makes it impossible to know when they were mailed.
Now, with the pandemic, these delivery times may have been extended in certain areas (that are constantly changing based on conditions on the ground) due to variety of issues, some of which will not be fixed by merely throwing money at them. You combine that with most states requiring that ballots be received by election day, at the latest, but no more then four days beforehand, and the whole thing is destined to become a mess.
If you mail early to make sure you votes gets in in an area where the mail has not been effected, it may be received too early and invalidated. If you mail it in on time but suddenly there is a delay in your area, your vote may get invalidated by being received too late. Then combine that with the large number of people who will forget to sign and a lot of ballots will be thrown out this year.
Like I said, if you want to go down this road, be my guest. Many more Dems plan on voting by mail then Republicans, and after the NYC primary and Iowa caucus it really seems like the Democrats need to learn the hard way.