Is 'impermanence' skillful means? Is 'impermanence' skillful means?

Wikipedia's definition of "Skillful means" says:


  The implication [of skillful means] is that even if a technique, view, etc., is not ultimately "true" in the highest sense, it may still be an expedient practice to perform or view to hold; i.e., it may bring the practitioner closer to the true realization in a similar way.


And of Impermanance:


  The doctrine asserts that all of conditioned existence, without
  exception, is "transient, evanescent, inconstant". All temporal
  things, whether material or mental, are compounded objects in a
  continuous change of condition, subject to decline and destruction.


I think that, for some Mahayana schools, everything is skillful means. So is the doctrine of impermanence "skillful means" too?

I am looking for an answer which:


Says yes or no (and explains why)
References a sastra or sutra (if there is one) which claims or implies this answer
Preferably, also, explains what (if any) bearing that may have to understanding any other doctrine: such as anatta; voidness; or the buddha-nature.
Well in one sense impermanence is ultimately true. In the other sense though it's just a concept, an idea, used to make a point. The objective of the point is to preempt grasping for things as if they were permanent, and the purpose of non-grasping is prevention of suffering. But even prevention of suffering is merely one of many motives that leads a person to enlightenment, other motive for example being perfection or conceit. In this sense everything is just a skillful mean inasmuch as it pushes some people in the right direction.