Digital Light & Color

In some situation it might be handy to have a "Dummy Transformation", i.e. a transformation that does nothing :-)
Let me explain a scenario.
I want to compose two images with the Composite Transformation
- I open the two images in PWP8 (image_a, image_b)
- I open both images in the Composite Transformation
- I select the wanted operation

That is a normal workflow.

But now I want to blur image_a and increase the saturation of image_b
So I start the blur transforamtion on image_a and the saturation tranformation on image_b
and start a new Composite Transformation.

The idea with the "Dummy Transformation" is this:
On both images (image_a and image_b) I run the Dummy Transformation.
The resulted images a opended with the composite transformation.
So far no change or the result of the Composite Transformation.
But now I am able to insert a transformation between the original image and the "Dummy Transformation", for example a Blur Transformation.
The result is passed over to composite transformation, since the "Dummy Transformation" is "linked" to the Composite Transformation and not the the orignal image.
I know, I can "misuse" nearly any transfomation as a "Dummy Transformation" by setting the Amount to 0%, but a dedicated Dummy Transformation would be nice to have .

If I understand the problem you are trying to solve with the dummy transformation it relates to transformations such as Composite that accept auxiliary inputs. While you can insert a new transformation between the regular input (the base image) and Composite, there is no way to insert a new transformation between the overlay image and Composite, so you need to manually select the new overlay image within Composite.

Is this a correct interpretation of your question?

Yes, it might be usefull for all transformation that accept auxiliary input: composite, filter, etc.
For instance, I want to replace a blown out sky in an image with the filter transformation. I create a mask and use an image with a nice blue sky as an auxiliary image. This image must have the same size in pixel as the "main" image. Ok, I resize the "sky image" appropriate and use this as the auxiliary image. Since I have different "sky images" in stock I choose another Sky and drag-and-drop it on the first shy image. It will be resized and the Filter Transformation will show the result with this sky.
I would like to be able to manipulate the auxliary image. Therefor I would not link the original auxiliary image but the Dummy Transformation.
By this I am able do any kind of manipulation to to the auxiliary image without changing the "calling" transformation. It is like some kind of (dynamic) subroutine that can be changed without changing the calling routine (composite, filter).

OK, I understand.