NEXT-31249 - mention overriding transport and lowering the priority

guides/plugins/plugins/framework/message-queue/add-message-to-queue.md

@@ -98,6 +98,32 @@ public function sendMessage(string $message): void
 }
 ```
 
+## Override transport for specific messages
+
+If you explicitly configure a message to be transported via the `async` (default) queue, even though it implements the `LowPriorityMessageInterface` which would usually be transported via the `low_priority` queue, the transport is overridden for this specific message.
+
+Example:
+```php
+<?php declare(strict_types=1);
+
+namespace Your\Custom;
+
+use Shopware\Core\Framework\MessageQueue\LowPriorityMessageInterface;
+
+class LowPriorityMessage implements LowPriorityMessageInterface
+{
+}
+```
+
+```yaml
+# config/packages/framework.yaml
+framework:
+    messenger:
+        routing:
+            'Shopware\Core\Framework\MessageQueue\LowPriorityMessageInterface': low_priority
+            'Your\Custom\LowPriorityMessage': async
+```
+
 ## Encrypted messages
 
 As the sent messages may travel through some 3rd party services you may want to encrypt messages containing sensible information. To send encrypted messages simply use the `encrypted.messenger.bus.shopware` rather than the `messenger.bus.shopware` message bus. The encrypted bus will handle encryption and decryption for you.