Stability & Regression Testing

## Description
Verify that existing data transmission remains stable after cleanup changes.

## Tasks
- Run end-to-end tests (X-Plane → Relay → iMotions/Mock)
- Validate data rates and synchronization
- Document known issues or edge cases

## Acceptance Criteria
* [ ]  No regressions introduced
* [ ]  All existing metrics transmit correctly
* [ ]  Results documented in test notes
