What it does
When this is on, Shake It On switches off cursor motion entirely and instead holds an IOKit power assertion that prevents user-idle system sleep. The display can dim, sleep, lock — the Mac stays running.
How it works
Shake It On creates a `kIOPMAssertionTypePreventUserIdleSystemSleep` assertion via `IOPMAssertionCreateWithName` and renews it every 30 minutes. While the assertion is active, the engine doesn't post any cursor events — there's nothing to wake the screen. All your Only Shake If conditions still drive whether the assertion is held; Paused When still releases it.
Where to find it
Settings → General → Allow display to sleep while shaking. The 'Display is off or locked' pause-when toggle is automatically disabled (greyed) when this mode is on.
When to use it
Overnight renders, backups, downloads — anything you want to run with the screen off. Pair with sustained-CPU and external-disk conditions for the perfect 'render in peace' setup.
How it compares
Lungo, Theine, and Amphetamine all have a comparable mode. Amphetamine's is per-session; ours is global but composable with Sessions if you want per-session behavior.