I hope you guys do well, I'm a big fan of the open core model and I really enjoyed using TipTap. This is the client I integrated TipTap with if you're interested in collecting examples in the wild: https://bundleiq.com/
Oh I just did some web development work for them a little over a year ago, where I added collaborative editing. It's an AI-powered note-taking app, with several integrations like Notion and (I believe) Google Docs. I haven't worked with them in a while so they may have changed their model, but once you give them permission they ingest all of that data and weave it into your own notes.