In the desktop version of 2024 TurboTax you can use the What-If Worksheet to accomplish what you want by marking the Use 2025 Tax Tables box for Column 2 and copying Column 1 to Column 2.
In 2025 TurboTax you can enter everything in forms mode, but don't do this with the actual tax file that you will be using to file your tax return. Do your actual tax return using step-by-step mode once all of the necessary features become available.
