Displaying deformation scale as a text

Hi, is there a way to add a text filter (maybe Python annotation) showing the deformation scale once a Warp by Vector filter was applied?

Python Annotation, 3D Text, 2D Text…

Yes, I know that I can use those filtes, but is there a variable to put in order to avoid put it by hand?

There is no specific mechanism to display the value of a Property of a filter in the 3D view.

Of course this could be done via a plugin, but it may not be easy to implement.