REQUEST: can we get a way to pick default entries when setting up a Form?

Can we get a way to pick default entries (here I am looking for a way to populate a List Formatted Line Item) when setting up a Form?
I would like to have certain selections auto-populated based on which of two Action buttons a user clicks.  They both result in adding an item to the same list.  But I want to specify the setting of a List Formatted Line Item based on which button was clicked.