Once upon a time, I tried to make an object of two instanced meshes: R E T R O B O Y (Tetrahedral deconstruction)
Another option is to use a so-called “batched geometry”, built of merged geometries, where each part has its own index so you can do some stuff in shaders, using that index. Something close, I could quickly recall of, is this: Tetrahedra (fat lines, batching, texelFetch)