I recently rant into a significant issue where I was going to add my first device that required a network_key set for secure mode.
Since the configuration.yaml nolonger does anything it was very frustrating to find out that the GUI has NO WAY to UPDATE ANY of the settings in https://www.home-assistant.io/docs/z-wave/installation without removing and restarting the integration or editing .storage/core.config_entries .
IT looks like the future will be stripping out direct Zwave support and sticking it in a plugin / external module over MQTT but it would be nice to at least be able to fix some core settings like the network key etc.