Comment # 10 on bug 895447 from Marius Tomaschewski

The only possibility to workaround it in yast2-network I currently see,
would be to implement the "switch away from NM" like this -- and also
to document in the release notes (for users doing it manually):

  # bnc#895447: NetworkManager does not cleanup on stop
  # Ensure it is gone along with conflicting dhclients,
  # ... before we switch over to another network.service.
  systemctl --kill-who=all kill NetworkManager.service
  systemctl stop NetworkManager.service
  systemctl disable NetworkManager.service

Is this the way preferred by the NetworkManager?