Command line –setParameter values are applied in applySetParameterOptions() (server_options_healpers.cpp) via ServerParameter::setFromString() which runs during the StartupOptionStorage initializer phase (EndStartupOptionStorage). No ordering edge exists between any query knob components and EndStartupOptionStorage, so the snapshot can be setup before the command-line value lands in the global ServerParameter but before the listeners are registered.

To address this, the listener initialization should be executed before BeginStartupOptionStorage. This ensures that both:

• Default values are captured correctly.
• No delta is lost.