tl;dr large gaming performance over stock CPU scheduler when there is a heavy CPU task running in background

Obviously, they only tested one game and it may not apply everywhere or hurt performance/latency in some cases.

One thing I wasn't aware of is that sched-ext/ePBF supports changing CPU schedulers on-the-fly, which takes away one of the downsides of third-party schedulers. I.e. you can use the stock scheduler most of the time, but then switch to a third party scheduler for specific workloads. So less of a downside risk.

Finally, none of this is merged yet (including sched-ext) so it's out of reach if you are just using the stock kernel.