yes on the safe harbor recap I see my typo there thanks for clarifying. there're more guidance on this topic here
https://turbotax.intuit.com/tax-tips/irs-tax-forms/what-is-form-2210/L2z0haVWb
Yes 2210 AI can be a pain to do, depending how complex your situation is and whether it's worthwhile depends on how much penalty you are trying to eliminate. You're doing mini tax returns for each quarter, and have to self-calculate the AGI i.e. replicate lines 1-11 on Form 1040, splitting up your income and any line 10 adjustments etc. Turbotax won't guide much it just asks for those inputs then does the rest of the form 2210 mechanics - the annualization and tax calcs, and needs breakdown of LTCG/Qualdivs and withholding to do that. There's probably other 3rd party advice on it if you do some searches and also go thru the Form 2210 instructions.
There's one other option which still involves some penalty but I'll put it out there, which is to adopt quarterly ES payments late, and quickly catch up your Q1-3 ES installments now to stop the penalty accruing, then pay Q4 in January. At this point (mid Oct) your Q1 installment is about 6 months late, Q2 is about 4 months late, Q3 is about 1 month late, with an annual penalty rate for 2025 of 7%. So for example if your total ES due was 10k for a quarterly ES of 2.5k, the penalty at this point if you catch it up should be (roughly) $2500 * (6+4+1)/12 * 7% = $160.
If you do not pay any ES at all then by default and without the AI method, for the same example, your final penalty by mid April would be roughly 2500 * (12+10+7+3)/12 * 7% = $467.
(if my penalty math is correct)
Beware also the $250 penalty last year may have been based on a lower safe harbor based on your 2023 tax which won't apply this year if you've being doing sizable Roth conversions since 2024, and the 'default' penalty if you do nothing could be much higher than last year.
One tip if you are using desktop TT, in forms mode you don't see Form 2210 by default, but if you double-click line 38 on Form 1040 then double-click the same line in the worksheet, TT will then show the 2210 form and penalty calculation.
Hope that helps.
