Consider deprecating old controllers API

**Problem**
When working with components, the error messages could be more descriptive.

**Suggestion**
Improve error handling and add detailed error messages.

**Context**
This would help with debugging and maintenance.

The issue names no files, tests, or entry points; start by locating the controllers API and reviewing its current error paths. Clarify whether the intended outcome is deprecation, more descriptive component errors, or both, then define the affected callers and verification needed before treating the work as done.

Written by the indexing model from the issue text.