Hi!

This diff proposes a vertex group control for the MeshCache modifier, to allow blending the imported cache with the modifiers stack above the MeshCache modifier.

This is particularly useful for instance when dealing with cloth simulations performed in another software, where some parts of the cloth are completely pinned (non-simulated, following the armature). Indeed, this would allow modifying the animation in some areas without having to rebake the other parts or the cloth, resulting in a much more flexible workflow.

Little demo, with the default cube: