Handle edge cases in filtering

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

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

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

The issue names no files or tests. Start by identifying how configuration options are defined and how model import is currently handled, then confirm the expected behavior of enable_import=false and the success criteria before assessing implementation and tests.

Written by the indexing model from the issue text.