@Mothership.Entertainment, I think you’re right - I think that InstancedStaticMeshes give you instanced rendering, so it basically just has the one vert/index buffer with different transforms (or whatever - don’t know how it’s handled precisely in UE4).
That said, overall it’s still going to be way faster for what you’re doing to simply write a custom actor class that sets up your mesh dynamically (if I’m guessing right that you’re interested in the instanced behavior to fix your performance issue from your other thread). This type of instancing behavior is mostly useful for cases like foliage where you have a ton of one mesh being drawn and the only thing that is really different is the transform/scale.
It will have a lot fewer verts to send, only one transform, etc. if you do it by building a custom mesh, and if it doesn’t rebuild super often the performance impact should be minimal (you could also set it up with a static index buffer I’m guessing, though that may complicate things).
I can understand the reluctance to do that, setting up custom meshes in code tends to be a pain.