It should be noted that instanced meshes do not support lightmaps, thus do not support indirect lighting, and do not support collision in the current build. Thus they can pretty much only be used for foliage, distant things, or special FX.
You can however spawn regular meshes also in about the same way. That is what I do for my plants. Later on if ever instanced meshes work better you could then just switch that around in the BP.