Can we use FSM Task API to export and update the Manage Standard Memo Lines for ongoing maintenance

Summary:

We have memo lines on invoices as we don’t have products. There is no API available for importing/updating Memo lines. The only option seems to be leveraging FSM Task API to export the file, make updates to the file and upload the file in the same environment. Hence wanted to get expert advice on the following:

1) Can we use FSM Task API to export and update the Memo lines (Manage Standard Memo Lines) files for ongoing maintenance

2) Will there be an impact on the Invoice tables and referential integrity of the invoices after the memo lines update