Custom Python libraries and Ren'Py 8.x Python ABI compatibility boundary

Ren'Py 8.0 and later defaults to the GL2 renderer and bundles a newer Python interpreter, with later 8.x releases moving from Python 3.9+ toward Python 3.11 and removing Python 2 support entirely. Projects migrating from Ren'Py 7.x may rely on custom Python libraries that include C extensions compiled against an older Python ABI.

The standard library availability and window initialization change with the rendering backend, and persistent data serialization is version sensitive. The precise compatibility expectations for third-party compiled extensions across the major Python ABI boundary are not clearly documented.

What is the documented compatibility policy for custom Python C extensions when upgrading from Ren'Py 7.x to Ren'Py 8.x? Is there a supported ABI range or rebuild requirement for bundled wheels? How should projects assess risk for compiled dependencies under the GL2 and Python 3.11 defaults?