True. I'm currently in the middle of writing a paper on extending Kubernetes Scheduler through Scheduler Extender[1]. The process has been really painful.
[1]: https://github.com/kubernetes/community/blob/master/contribu...
[1]: https://github.com/kubernetes/community/blob/master/contribu...
[1]: https://github.com/kubernetes/kubernetes/pull/13580
[2]: https://github.com/kubernetes/enhancements/blob/master/keps/...
EDIT: formatting