Add configuration options for backup

**Feature request**
It would be great to have export for controllers.

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

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

No files or tests are named. Start by locating the configuration definitions and the controller export path, then trace how existing options are loaded and how controller data is handled. Done means an `enable_export` option defaults to `false` and controls the requested controller export behavior, with coverage for the default and enabled cases.

Written by the indexing model from the issue text.