How to switch from MFS to MFJ (and vice versa) in Scenario Analysis
First, upload each MFS tax return as normal into the couple's household (Note: because you are uploading two separate returns, each one counts towards your total uploads for your subscription year). Then, enter the two separate MFS tax returns, do not copy them, into Scenarios 1 and 2. In the 3rd Scenario, manually add the numbers from Scenario 1 and 2 into the new Scenario 3. You can do the same for a MFJ couple who wants to see what it would be like to file separately, just in reverse.
To change the filing status, you can do so by expanding the filing status bar in Scenario Analysis as shown below.