Want to reduce latency? There's now a free and open source way with LatencyFleX, that gives a vendor and game agnostic latency reduction middleware that you can try out.
This can be used as an alternative to NVIDIA Reflex, for Windows games running through Proton that have it implemented directly, plus certain Linux builds of Unreal Engine 4 games and as a plugin / hook for Unity games too. An advantage of course is that you don't need an NVIDIA GPU, with the developer mentioning one of the motivations for creating it being only having an AMD GPU.
Plans also include to enable developers to integrate it into their game engines too. Overall it sounds like a really fantastic project and could be fun to try out.
For a little more behind the scenes, you can check out the introduction blog post.
The project is available on GitHub under the Apache 2.0 license. Use at your own risk, especially games that have some form of anti-cheat.