However as I have pointed out DAVDroid will not allow me to access any screens for setting up caldav or carddav paths. It first wants some sort of BaseURLs configured.
Default Baïkal CalDAV base URL:
Default Baïkal CardDAV base URL:
You don’t have to get into further screen, just enter the base URL in the first screen.
For more information about well-known URLs and service discovery, see DAVdroid: Service discovery. However, I don’t know whether and how this would be applicable to Baïkal running on Synology devices.