Consider deprecating old middleware API

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

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

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

No files, entry points, or tests are named. First locate the middleware API and configuration handling, then clarify whether the goal is deprecating the old API or adding the `enable_import` option for hooks. Done should include an agreed behavior, default setting, and tests for the selected change.

Written by the indexing model from the issue text.