Hi,
The “Import/Export” area allows to import and export the forms of your WordPress, and the format used in the form files is not CSV.
If you want export the submitted information to a CSV, you simply should press the “messages” button corresponding to the form, and press the “Export to CSV” button:
https://cff.dwbooster.com/documentation#export-submissions
The CSV files are used too in our plugin as datasource for some of “DS” fields, the fields with multiple choices (DropDown DS, Radio Button DS, Checkbox DS). Simply, insert a DS field in the form, and select CSV as the datasource option. The action allows to select the CSV file to be associated with the field.
Best regards.