Exporting views includes all of the content. This example removes a "View more" since it isn't needed in the view.

add_filter( 'frm_export_content', 'change_exported_cell' );
function change_exported_cell( $content ) {
  $content = str_replace( 'View more', ' ', $content );
  return $content;
}

Use the code below to replace the ampersand HTML in exported field.

add_filter( 'frm_export_content', 'replace_ampersand' );
function replace_ampersand( $content ) {
  $content = str_replace( 'amp;', ' ', $content );
  return $content;
}

Use this code snippet to add the apostrophe if the value looks like anything but a number with some periods or dashes. If you have removed '+' from the risky characters list, this will add the apostrophe for potentially risky cells but removes the apostrophe before the '+' sign for phone numbers.

add_filter(
	'frm_export_content',
	function( $cell ) {
		if ( '+' === substr( $cell, 0, 1 ) && ! cell_is_phone_number( $cell )  ) {
			return "'" . $cell;
		}
		return $cell;
	}
);

function cell_is_phone_number( $cell ) {
	$substring = substr( $cell, 1 );
	$substring = str_replace( array( '-', '.' ), array( '', '' ), $substring );
	return is_numeric( $substring );
}