BF4 is 900p though. Are we guessing the HUD and OS menu stuff would be on the same plane then?
Well, I mean, you have the PS4 OS. That is running at 1080p. The OS UI doesn't need to be upscaled. Then you have BF4. That is running at 900p. That means the the hardware scaler needs to upscale BF4. It doesn't need to touch the OS. Now, in addition, DICE may have rendered the HUD at 1080p and the actual game render at 900p. So if that were the case, only the game render needs to be upscaled. But I'm saying that, since the PS4 OS UI is rendered at 1080p, the two planes for hardware upscaling would be the HUD elements, and the game render.
Now, if you're talking about the GAME MENU, then yes, I would lump that in with the HUD elements on the same plane.