With respect to messed up 2021 Form 2210 AI line 14 calculations, I ran a check to verify my spreadsheet, which is based on IRS Pub 505 Worksheets for Form 2210, was correctly predicting line 14. I went back to 2019 TT Form 2210 and compared what the spreadsheet calculated for taxes due line 14 to what my spreadsheet predicted for that year and they matched in all periods. If TT had just used 2019 Form 2210 which has the same est tax periods as 2021, rather than using 2020 Form 2210 as a basis, there wouldn't have been all the errors in 2021 Form 2210 that they still haven't fixed.
