What is the usefulness of this feature?
The only advantage I see is that your clients can choose the format they want to work with, but since the serialization format is just a message format that has no impact on the code, and that most of them have a bijective transformation between them, I don't see the point.
If it feels like a lot of work (Or the added complexity of a moving part, if using the tool you linked) for next to no impact.