Replace WooCommerce Customer/Order XML Export output with a totally custom format :)

wc-xml-export-output-custom-format.php

<?php

function wc_xml_export_output_custom_format( $output, $order_data ) {

	$output = '';
	
	foreach ( $order_data['Orders']['Order'] as $order ) {
		
		$output .= "--START ORDER--\n";
		
		$output .= "ID: {$order['OrderId']}\n";
		
		$output .= "--END ORDER--\n";
	}

	return $output;
}
add_filter( 'wc_customer_order_xml_export_suite_generated_xml', 'wc_xml_export_output_custom_format', 10, 2 );

/* This will render the output like:

--START ORDER--
ID: 190
--END ORDER--

Note that you can use other filters in the plugin to change the file extension and content-type (for download) if desired.
*/