Hi Burr.
Yes... obviously testing would be easier since you don't need to deal with ConfigTree... just use setters. The @ConfigProperty can also be placed on a setter instead of the field.
As for an example config, you'd just need an action beforehand that performs a "to-Order" transform, setting the created Order on the Message payload.
Also, as hinted to above.... we could support auto-binding (unmarshalling).