You can find these settings in the section 'Fast Input' in the menu 'Settings' > 'General'.
When you enable this option, you don't have to check UBL files that were imported in Fast input. All information in a UBL file has a fixed location which means you don't need to check UBL files again during import.
Enable this option to skip the check and have imported UBL files appear immediately in the list of expenses or income. The customer or supplier info will also be included in the customer or supplier list.