Improve controllers performance

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

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

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

Start by locating the controllers and configuration entry points involved in API imports. Determine how production deployments currently handle this request, then define the behavior controlled by `enable_import`, including its default-disabled state; done means the import functionality is available when enabled and unchanged when disabled.

Written by the indexing model from the issue text.