What method should be used to annualize my South Carolina required annual payment? This was due to year end Roth conversion. Any assistance appreciated.

I performed a year end Roth Conversion and paid the associated estimated taxes at that time. Using TurboTax I completed federal form 2210 and annualized the income using Schedule AI, which computes the annualized income and associated federal tax due for each quarter. However, for South Carolina state taxes TurboTax does not define a method to be used to calculate the quarterly taxes. Reviewing the instructions for South Carolina Form SC2210 yields more confusion as it implies using the information as indicated on the Federal Schedule AI line 27, which of course is the federal tax. What would make sense to me is using the method of Schedule AI using the AGI and deductions from the South Carolina SC1040. Any assistance would be greatly appreciated.

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