@Smokeball even if you could set up dummy return s online you would probably have to pay to see them.
desktop allow you to create as many what-ifs as you like and you only pay once for the app.
warning Turbotax's initial release of desktop/online is beta. it will contain some changes in effect for 2023 but not all. As you know tax laws change from year to year and the apps are not set up to do tax projections for future years. In effect you would have to do a lot of guesswork and make your own assumptions as to how years past 2023 would work out
