My brokerage does not have all tax forms available at once. When I import the forms that are available and then try to import other forms as they become available by selecting only those new forms, the previously imported forms get deleted. If I choose to select all available forms for import, the previously entered forms get overwritten and all the updates I did are lost. How can I import the available forms and make the required updates and then later import other forms as they become available without deleting or overwriting the forms I have already updated?