Controlling the use of beacons
inline_images filters, use a beacon to collect information about the rewritten page so as to optimize the rewriting process. The beacon is a
pagespeed CriticalImagesBeaconEnabled false
If you disable image beacons but enable filters that use them, the filters will work but not as well as when beacons are enabled.
This directive can be used in all scopes including location-specific configuration sections.