WIll skinned-mesh cubes with 8 bones on corners in big amount (like 16^3+) lag a lot, if bones won't move?

Hello, guys. I want try to make mining part to my game. For it I want to use cube-based grid. But for better realism, I also want to try to make cubes of stone/ores to be skinned meshes with corners which can be displaced a bit with bones. Bones will be calculated only once, so no any dynamical changes. But still I have question - will this cause lags if there’s a lot of cubes?

Most definitely. Even if the bones aren’t moving, they still exist, and the mesh is still skinned. For what you’re getting its not worth it, you might as well pose the bones in Blender or whatever software you use and export it as an OBJ so the mesh isn’t skinned but keeps your edits.