We ran a few tests on the with a 4.10 project and at first I was running about 75 FPS but after the following changes I was able to get the back up to 90 FPS.
- First I set the Directional light from stationary to static and added a static sky light and then re-built the level lighting.
- Next I added a PP Volume, set it to unbounded and then turned off the following features.
- Bloom was set to .225
- Auto Exposure Min and Max Brightness was set to 1
- Lense Flares Intensity was set to 0
- Set AO Intensity to 0
- Screen Space Reflections are set to 0 for intensity and quality
If you do all of the above and they are still having issues then it is most likely a content issue. If this is the case you could check the link below for information on performance profiling.
Link: Testing and Optimizing Your Content | Unreal Engine 5.1 Documentation