Introduce cluster-wide pre-image expiration parameter indicating a number of seconds to pass after the change event occurrence when the system can purge any state required to provide pre-images for the change event.
Gate this functionality with a new feature flag dedicated for time-based pre-image retention policy.
Store the parameter in memory and don't propagate it throughout the cluster - neither from the config server to shards, nor from the primary to secondaries. Hide property persistence and propagation in the cluster concerns in a placeholder module to be replaced with a proper implementation in scope of PM-2502 that will use mechanisms developed in PM-2502.