I’m not sure why the new in editor option is there, maybe to fix some issues with view modes since they all need to be set up for Pre-Exposure individually. There is overhead on the renderthread using it, but I have never profiled it or felt like it impacted much compared to the rest of the scene rendering, but it’s also entirely dependent on the GPU as overflow varies per brand and series. It’s not necessarily *needed *per se, but it can be beneficial to catch any/all issues with overflow on different video cards in which case it would be needed, or you need to reduce the maximum value of the scene.