The download version of TurboTax has a What-if Worksheet available in forms mode. On that you can make entries and mark a checkbox to use 2024 tax tables.
You can also prepare a simulated 2024 tax return with 2023 TurboTax, but you'll need to override various cost-of-living adjusted values to use the 2024 values. On the What-if Worksheet you can then copy the results from column 1 to column 2 to be able to apply the 2024 tax tables. This is what I do every year.
