Sorry for the late email. I was focusing on tackling the Result plugins. In the past weeks, I have stablize the survey_engine and builder engine to adapt new code. The model's code for saving results is working now with the test available in rseult.test.php ( this isnt adapted to the latest changes of how to record answers in result.php yet ).
One big progress is the ability to write plugins (using Behavior) for Result.php without having to modify the Result model itself , thanks to CakePHP's ModelBehavior::attach() and Model::__construct(). From now you we can write plugins and use their methods in controlller directly as if they are belonged to Result model themselves. Therefore I expect the core Result.php will be minimal and only consists of main functionalities. The rest can be added via Behavior plugins.