Hello!
- Sorry for my English
Often after blockout lvl => production i have a tons messages into Map Check " SM_actor_name have Null static mesh property"… sometimes it around 10-20 messages. Sometimes it around 400-800 
Cause this SM actors are not needed for me… i delete them, but delete 200-300 empty actors a little boring
so i made a BP, for 1st tests it works fine.
Yeap - i know, what i not need to set array and make branch for manual delete, i made it for tests.
Or i do something wrong? or i have button in editor UI for this?(