I just got finished "catching up" on that online.  He seemed pretty adamant about not extending anything beyond 5/17 and not extending 1Q-ES payments beyond 4/15.  His argument was normally on 4/15 they pull a bunch of people off the phones to deal with correspondence.  Now that will have to wait a month so anyone stuck in limbo (a.k.a. the "backlog") awaiting problem resolution will likely be stuck for 30 days longer because the people who can help them will be too busy answering the phones.  Not sure I buy it, but that's what was for sale.  I'm sure there's some truth to it.

He was quite confident that the IRS can simply recompute already-filed tax returns once they get the unemployment data from the states, which is due 3/31.

That still won't help anybody who needs a superseding return to change filing status from MFJ to MFS if they were screwed by the $150K MFJ MAGI limit.  IMO those will still need to be paper filed by the due date.