Well, you can use the edit function to remove any * for the next paper, before you start. (maybe using the “edit>find and replace” option to replace the asterisk in the label field with nothing.
If I were trying to keep track of records in a paper, I wanted asterisked (especially if multiple papers required it at one time), I would create a group to contain each set. Do the above step to remove any previously askterisked records and then when I was needing a group of citations to contain the asterisk in a new manuscript, you could select that group and use the tool>change/move/copy option to replace the label field with the asterisk for that set of references.