I am not an expert in shaders, but as far as I understand in order to animate vertex position on a screen with shaders this feature should be incorporated in the game engine and have a serious chunk of codes per specific mesh/actor or group of actors. Animated shaders in this case are used together with bone animation for better bending/morphing (MW and OB engines do not support skin gizmos). I am talking exclusively about bone animation, and not about something like sea waves and water that ripples. MW and OB do not have kfm files that contain animation blending parameters specified by an animator in the process of working with animations (engine package has standalone software for that e.g. AnImmerse in older versions). So, in case there is any blending of skeletal animation IMHO it is achieved solely via game engine programming.
Yeah, in Morrowind the engine sets height and weight with a scale key on the animation root. It would be possible to set it per NPC through the NPC's animation controller, the main problem is tools for creating, loading, and storing extra information like that in a compatible way.
Hence, MW game engine set these parameters globally, not on per animation level. This means that without external coding such feature cannot be achieved. On NPC animation level Dirnae (discoverer) and I have already tested that.
OB has a separate skeleton nif for a specific race or NPC (it was changed in the recommended OB mod). MW does not have that: skeleton structure is stored in x.nifs (base or NPC attached) that is dynamically used by the game engine. So, OB approach is not applicable in MW.