some other things. the desktop but not online has what is referred to as forms mode. this can be used to correct issues that prevent efiling. also you can create as many versions of your return as you want but be careful to file only the actual one. This does allow some tax planning/what-if scenarios, but they will be based on the tax laws for the year of the desktop currently 2023. There is also a section in the estimated tax portion to allow limited tax planning for 2024 but again not all 2024 tax laws are reflected.
