Did you read that before you posted it? I’m guessing no, although it doesn’t surprise me.
You were the one coming in trying to be smart talking about “malloc” and “new” and memory management yada yada, I was saying they would probably not check if the item exists in a function that “could” be called millions of times a frame (like in CGI which the engine supports) and that code would be checked in a development build, but since your writing a game engine you probably knew the performance benefits of that already, and yes occlusion, again in CGI which is prerendered you render everything that may be relevant even the stuff hidden by other meshes for more accurate shadows/colors etc, you don’t seem to understand unreal engine supports more then just games and has to perform each of those tasks well.