Don't know, if I understand what you mean.
In blender I've heard the term "morph target" as an addition to bones animation - maybe, I understood that wrong, though.

The model format of 3DGS mdl offers two sort of animations: vertex and bones on a frames basis.
A frame with a certain vertex animation could be such a morph target via ent_blend.

But, only when you don't use bones animations in this model as well, because then the engine ignores the vertex animation.