Looking further - I see that the Schedule AI line 7 is not including the amount from line 12b on form 1040 - that 12b is the amount of cash charitable deductions (max $600 for married, filing jointly), so it is only getting the standard deduction amount - NOT Std deduct + Charitable contribution, which would make you have a lower annualized income and therefore less tax to pay.
When I looked back at my 2020 version of form 2210, it too also seemed to be incorrect in a few places.
