I've tried BO4 and I cannot tell if it's working or not. However, the loading screen that pans the map you about to load into is a lot smoother now. OSD still shows fluctuation in frame rates as it loads but the screen is smoother still.
I do melt a few but not 100% sure yet, still testing. However, we need something that actually show's the difference while playing is the best I can say. It actually might be working but there is no way to tell as there is no OSD indicator at this time. Perhaps RTG will implement something in the future.