SPARK-22799 and SPARK-22797 are causing valid Python test failures. The reason is that Python is setting the default params with set. So they are not considered as defaults, but as params passed by the user.
This means that an outputCol is set not as a default but as a real value.
Anyway, this is a misbehavior of the python API which can cause serious problems and I'd suggest to rethink the way this is done.