It would be great if Joplin had a "live edit" mode with multiple simultaneous users adding text, just like Etherpad, HedgeDoc, HackMD and others allow, keeping the experience within the Joplin app.
The sync code is OSS, and one would simply have to provide a sync server and login credentials (if required).
We use this in self hosting, which is easy with Cloudron, which includes Etherpad and HedgeDoc already, and would be easy to point to in our infrastructure.
This would also have the added benefit of zero conflicts and no need for resolution as that is taken care of during live editing.
(We have multiple users editing the same document in a pair coding/documenting process, which makes this flow stop every time there is a conflict.)
And come to think of it, WordPress devs wanted to do this with Gutenberg blocks, which has moved to the Sync Editor - using Yjs, which seems to have many implementations.
Nextcloud Text uses tiptap as well for their collaborative text editor with markdown.