The Form screenâs sole purpose is to add rows. As soon as you click on the submit button, it adds the row. Thatâs what itâs designed to do. A Form screen is not meant to edit an existing row.
You may need to use something like âShow New Screenâ and create a custom edit screen to update an existing row.
You canât have different Edit Screens. You an only have one Edit screen and itâs permanently linked to the table.
A custom action could write special values to certain columns before opening the new screen. Or you could set up your custom edit screen so you fill user specific columns, and then add a button that writes those users specific values and special values to the existing row.
I donât know that there is any specific documentation on âThis Itemâ, but what you are doing there is essentially creating whatâs commonly referred to as a Custom Form. To learn more about that, you can make a copy of the concept app in the below thread and study it.
Even though there is only one edit screen, you can set visibility conditions to the edit screen components to have one set show under one circumstance, and another set show under another circumstance. This wonât always be the best solution, but it works great in some cases.