Optimize validation for large datasets

**Feature request**
It would be great to have notifications for hooks.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_notifications` with default `false`.

Start by locating the hook handling and configuration-loading entry points in the repository, then trace how a hook event is processed. Check how an `enable_notifications` option could affect that flow and identify existing tests or validation for configuration. Done means the option defaults to `false` and hook notifications behave as specified without changing existing behavior by default.

Written by the indexing model from the issue text.