Doing a new project with %JSON.Adaptor, unexpectedly realized that %JSON.Adaptor does not support export to native JSON. %JSONExport just outputs directly to the current device, and there are two more methods %JSONExportToString, and %JSONExportToStream.
In conjunction with generating REST from swagger specification, where any generated method accepts as a result %DynamicObject, which is good.
I have multiple places in my REST where I have to return JSON for an object, but I have to modify the result a bit, just extend it with some other way.