As far as I know, there’s no approriate equivalent for CardDAV (address books). Other possible mechanisms would be a group principal membership, but that’s currently very wide-spread.
Short answer: It’s a CardDAV limitation.
I configured a Woelkli account in DavDroid. I can see the account in the Calendar App but not in the Contacts App.
Have you tried Google Contacts?
@rfc2822 I wasn’t patient enough. I got fed up and took a nap. I just got up now and the default LG G5 contacts app sees the Woelkli address books.
Thank you for replying.