WooCommerce set default values in checkout page for shipping/billing fields. I used it to set a default city.

woocommerce_default_city.php

<?php
add_filter( 'woocommerce_checkout_fields' , 'default_values_checkout_fields' );

// You can use this for postcode, address, company, first name, last name and such.
// field names can be found here:
// https://docs.woocommerce.com/document/tutorial-customising-checkout-fields-using-actions-and-filters/
// found the main function woocommerce_form_field() here:
// https://github.com/woocommerce/woocommerce/blob/76b32c9aa52ebac70fe5a60a8d56351218760471/includes/wc-template-functions.php

function default_values_checkout_fields( $fields ) {
	$fields['billing']['billing_city']['default'] = 'SomeCity';
	$fields['shipping']['shipping_city']['default'] = 'SomeCity';
		 return $fields;
}

// and you can just use CSS to hide the inputs, you know.

?>

Is it possible to set default address only for some shipping methods and for others leave blank fields?