you don’t have to edit the order-details.php
page the woocommerce_order_details_after_order_table
action will achieve the same results.
add_action( 'woocommerce_order_details_after_order_table',
'namespace\custom_field_display_cust_order_meta', 10, 1 );
function custom_field_display_cust_order_meta( $order ) {
echo '<form [whatever]>';
/* translators: whatever */
echo '<p>' . sprintf( __( '<strong>Property 1:</strong> %1$s (%2$s)' ),
'<input [whatever]>'
. get_post_meta( $order->get_order_number(),
'property 1.1', true )
. '</input>',
'<input [whatever]>'
. get_post_meta( $order->get_order_number(),
'property 1.2', true )
. '</input>' )
. '</p>';
echo '[whatever]';
echo '</form>';
}