smallrye-config: Injecting an undefined Config Property value with an Optional Converter returns the wrong value

For the following ConfigProperty Injection:

@Inject
@ConfigProperty(name = "unknown") // where unknown is not defined anywhere
Optional<MyStringObject> unknownOptional; // where MyStringObject is a simple class with a get and set method for a String

Which has the following Converter:

public class MyStringObjectConverter implements Converter<MyStringObject> {

    @Override
    public MyStringObject convert(String value) {
        MyStringObject obj = new MyStringObject();
        obj.setValue(value);
        return obj;
    }

}

The SmallRye implementation returns the following unknownOptional:

unknownOptional.isPresent() -> true
unknownOptional.get().getValue() -> ""

According to the MP Config specification, I think this should be:

unknownOptional.isPresent() -> false
unknownOptional.get().getValue() -> Exception