Consider deprecating old store API

**Description**
Currently helpers lacks proper serialization support.

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

**Priority**: Low/Medium

Start by locating the helpers and the old store API, then inspect how values are currently serialized. The issue does not name files or tests, so first clarify whether the goal is API deprecation, configurable serialization, or both; done should include an agreed migration path and sensible default behavior.

Written by the indexing model from the issue text.