What is this Slate and how can I get rid of it?

I’m doing some optimization on my VR game-to-be using the Session Frontend and I get a fairly high ms attribution to a ‘Slate’ section.
I thought Slate was some kind of 2D interface thing? I am not using any 2D or other interface things in my level.

Does anyone know what this is and if it can be made to disappear?


EDIT: I read some saying that Slate was due to the Editor being open.
So I used the standalone Frontend to build and launch and then take a look.
Slate was still at around crazy 12ms!


From what I’ve read in other treads that slate time is just used to fill up frame time to get 90 fps. You can try it by adding some heavy effect and see if slate time drops.