Updated Release Testing Instructions WooCommerce 6.0 (markdown)

Release-Testing-Instructions-WooCommerce-6.0.md

@@ -137,6 +137,13 @@ Please test using Firefox.
 1. Add a payment method
 1. Immediately attempt to add another payment method
 1. Verify the error that you "tried too soon"
+1. If you're having trouble triggering the rate limit default, use this filter:
+```php
+add_filter( 'woocommerce_payment_gateway_add_payment_method_delay', function() {
+	return 60;
+} );
+```
+
 
 ### [Fixes #30400 by multiplying refund values by -1 #30957](https://github.com/woocommerce/woocommerce/pull/30957)