taxes are capped at $10,000 for 2018 to 2025
if the extra deduction will not produce a federal tax benefit (you owe less federal taxes), then it will be nontaxable in 2022. also long ago before the above tax law change, there was a Supreme Court tax case where to avoid the Alternative Minimum Tax taxpayers deducted less than the amount they paid for real estate taxes on schedule A. SCOTUS said for AMT they had to take the full amount into account.
your case is slightly different unless the full deduction would result in AMT.
also since the state withholding transfers from the w-2 to Schedule A automatically, you will have to override. this will prevent e-filing and void Turbotax accuracy guarantee.
