1. The test generating code is broken, and hard to maintain, see Fix test generation #89 and Fix cargo run --package gentest #65.
2. The automatic tests are massive, resulting in painful renames.
3. This strategy is extremely hard to apply to alternative layout strategies (Support multiple layout algorithms #28).
4. These generated tests aren't even complete, and have failed to catch multiple deviations from the spec.

These should be supplemented with a fuzz testing or property-based testing framework.