in method visible_columns()

mcp.freeform.php

			$default_hide = array('site_id', 'entry_id', 'complete');

			foreach ($default_hide as $hide_me_seymour)
			{
				if (in_array($hide_me_seymour, $visible_columns))
				{
					unset(
						$visible_columns[
							array_search(
								$hide_me_seymour,
								$visible_columns
							)
						]
					);
				}
            }

            $form_id = ee()->input->get('form_id');
            $layout = $this->composer_field_order( $form_id );

            if ( $layout ) {
                $sorted = array();
                $top = array();

                foreach ( $visible_columns as $column ) {
                    preg_match( '#[0-9]+$#' , $column , $match );
                    if ( $match ) {
                        $sorted[ array_search( $match[0] , $layout ) ] = $column;
                    } else {
                        $top[] = $column;
                    }
                }
                ksort( $sorted );

                $visible_columns = array_merge( $top , $sorted );
            }