ownCloud Infinite Scale and CalDAV (Calendars) / CardDAV (Contacts)?

[s-light]

as I just stumbled again over this topic in search results:

the newest info as fare as i found is in

Caldav/carddav with OCIS 4.x

Another question concerning migration from OC x classic to OCIS: from my understanding, after reading and it should be possible with OCIS 4.x to migrate calendar/caldav and adressbook/carddav data from a OC classic instance to an OCIS instance, as the required services and APIs are already present. Is there any other relevant information source for this?