PR is not complex and is important because of two reasons:
1. It blocks PR https://github.com/scipy/scipy/pull/18242. Hence, it will allow us to have Cython 3 Beta in scipy which can help us test Cython 3 better (already 2 bugs were found during migration)
2. It seems it will break several libraries so I think it is better to have it in master earlier to give users more time for fixing issues.