I am so glad I found your post, since the 'What if' worksheet is easier than my old method. I was already used to making a copy of the prior year return, and then editing (and re-editing) that one using the prior year TT. I still copy the old return for safety, but now I can use the 'What if' worksheet to make my edits for 3 scenarios. In short, I click the box 'copy column 1 to column x' and 'use this years tax rules'. As long as you allow TT 2023 to get its updates, the 2024 tax tables will be used when they become available. Nice. I had wondered why TT 2023 wanted to update when it is almost 2025, but this is one good reason.
TT 2024 has an issue that it won't let you enter your IRA distribution until Jan, preventing you from doing last minute tax planning. If you don't have TT 2023 to plan with, then the 'What if' worksheet in TT 2024 seems to be a way around that.
