Turn on Windows Game Mode
Lets Windows focus resources on the game in the foreground.
Applying it needs Nexus Standard or Pro. Every plan can read it here and undo it in Restore Center. Compare plans
What it changes
Sets HKCU\Software\Microsoft\GameBar\AutoGameModeEnabled = 1, the per-user value behind Settings > Gaming > Game Mode.
Before anything is written, the review screen shows this setting's current value on your PC next to the new one.
Why it helps
Microsoft documents that Game Mode stops Windows Update from installing drivers and showing restart notifications during play and helps achieve a more stable frame rate depending on the game and system. Gains, where present, are usually small.
Trade-offs
Very rarely a game or capture setup behaves worse; you can switch it off again here.
Evidence
Moderate evidence means: helps in specific situations. Expected impact is small (1 of 3): how much it can matter when this is actually the bottleneck on your PC, not a promised gain.
Is it in a pack?
Yes. It's in the Gaming performance pack, so that pack and Optimize everything include it. You can still untick it in the review screen.
How to undo
Switch the tweak off in Nexus, or open Restore Center and restore this change (or choose Undo last change). Nexus writes back the original value it recorded before applying, not a generic default, then reads it back to confirm.