Random number reproducibility

Question

Should the event sources have their own random generator instances so that if one is added/removed the distribution in the source will be identical.

The issue mentions event sources and their random generator instances, but names no files, tests, or entry points. First inspect how event sources are created and where random state is currently owned or seeded. The scope is not ready for implementation until the project decides whether per-source reproducibility is required and defines the expected behavior when sources are added or removed.

Written by the indexing model from the issue text.