Nanite is great but especially when you have more rounded sides and smaller meshes, Nanite folds on itself. You’ll get a mesh that looks like it’s missing a vert or had a flipped face. Test it out but I wouldn’t just convert and walk away without checking it. The level instancing will give you an actor like you want but without more advanced setup, you’ll need to go into the level to make changes to it. With the merge actors, (I know you said it wouldn’t work), but when you create the proxy mesh, you can add more proxy meshes to it. If you just copy that mesh you’ll see it takes a second or two to duplicate, but if you copy the mesh component inside, it’s instant and it’s a true instance of the mesh. Much cheaper and you can add it anywhere.