UE Basics Thread, Talking, Learning, and Maybe More

Question 15: I’m looking at layout design. Has the latest version 4 of Unreal Engine abandoned the idea of BSP, Block Out Brushes? I’ve found some older tutorials on it, but nothing for V4.7.

Has the idea of placing a box and designating it “Hollow” disappeared? This is also mentioned in older tutorials, but the only time I see a brush setting for a Box is when it is added as a “subtract” mesh. But can’t seem to get the subtracts mesh to actually subtract from a box already in a scene as if you are trying to cut a door into it.
I’m assuming that first the existing box would have to be designated as hollow or 2 sided, but I have yet to find the settings to change an existing box in the world.
Thanks!