As far as I know in UE4 if you create blueprints of your Static Meshes and then place them in the scene all the instances with the same material will get rendered with a single drawcall.
In this video:
Nanite | Inside Unreal - YouTube
from Epic, on minute 59 I understood that with Nanite meshes this might no longer be necessary; is that true?
Static mesh instancing is what you are referring to which is not the same as just adding a static mesh to a blueprint. The way nanite works, you do not need to use instancing for any meshes.