Why note? SI is flexible for those cases. Otherwise he will have to write custom `RedisSerializer`, who doesn't have so much common value as transformer:
```
<int:transformer expression="T (org.springframework.security.crypto.codec.Base64).encode(payload)"/>
```
Current behavior is more flexible: it allows to send different types by default.

Of course, we can change it to `&& this.serializer == null` if you want, but then we should do the same for `RedisQueueOutboundChannelAdapter`