Optimize helpers for large datasets

**Description**
Currently utils lacks proper export support.

**Proposed solution**
Add configurable export with sensible defaults.

**Priority**: Low/Medium

Start by locating the utils/helpers code and any existing export or dataset-handling entry points. Read how current outputs are produced and check whether tests cover large datasets. Done means configurable export support exists with sensible defaults, but the required formats and behavior still need clarification.

Written by the indexing model from the issue text.