I guess I shouldn’t be surprised if Google is up to nefariously trying to force something…
A functionality where someone can copy or move all calender entries or contacts from one DavDroid account to another would be fine.
This would made it easier to e.g. move from one provider to another.
Editing all calendar entries manually to move it from one account to another is just too boring
And editing of contacts in order to move it from one account to another is not possible (at least in LIneageOS 14.1).
For contacts: did you try Copy Contacts? I don’t know whether there are apps for moving calendar entries, but I guess so.
You can also export all contacts/events and then import them again into the DAVdroid account (works at least for contacts, but I’m quite sure that there are calendar apps which support import/export).
I understand the necessity of this feature, but it shouldn’t be implemented in DAVdroid, but in a third-party app, because