Libbyurner,
Your situation is similar to mine. FWIW, I snail mailed my guestimated 1st Quarter taxes yesterday (used last year's 2019 based safe harbor amount since my actual income was down in 2020) and will expect to get a refund 2x that later this month when I have time to complete my taxes. Seems goofy, but I didn't find a direct answer to the timing question, so errored on the safe side.
