At a quick glance this strikes me as an overly convoluted plan that might not work out the way you think it will.
There is no "full benefit" from itemizing deductions. If your federal itemized deductions are $30,000 and the federal standard deduction is $32,200, you get a $2,200 bonus for taking the standard deduction. You get to deduct $2,200 more than your actual deductible expenses. On the federal side there is no benefit to artificially inflating your deductions. Also, the IRS will sometimes question a deduction for state tax withholding that is unnecessarily high (though the amounts your are talking about might not be large enough to catch the IRS's attention).
I don't know what you mean by "the 1099G worksheet." There is no form in TurboTax called 1099-G Worksheet. So I don't understand how you think it would reduce your federal itemized deductions.
You also have to take into account that a large state refund for 2026 will be additional taxable income on your 2027 federal tax return. Is that where "the 1099G worksheet" comes in?
I think you should work through Schedule 511-D in the Oklahoma tax return to make sure you understand all the restrictions and limits. You might not be getting the deduction that you think you would get.
