Yes. We fully embrace the iCloud/CloudKit security model. All chats live in the private database of the owner, and are shared with others through the iCloud sharing facilities and the shared database. And yes, while it all goes back to iCloud share links in the end, we built our own layer of invitation links and connection requests on top of that, which provides you more support and context, until you finally have to accept the iCloud share link.

I agree it is an interesting feature, works well, and I wonder why aren’t more apps built with that. Perhaps one reason is that the developer experience is somewhat esoteric. It took me quite a while to figure out how it all works and how to put all the pieces together.