Switching Material and Mesh using keyframe in Sequencer (for mask rendering)

@WilliamFaucher Hello Everyone I have a question I am being able to apply different material to same mesh using keyframe in sequencer, but at the same time I want the mesh to also change, what is the best method to do so? It is regarding mask renders only not blueprints(not for play mode). Also wanted to know can we change materials of a group of objects/multiple objects at the same time.

Actually I have a tried using actors hidden in game in a sequencer, just wanted to know is there any other method to do so.

Thank you in advance.