Disclaimer, I'm on AFFiNE's team. But I really think you can check us out as I think we can cover those boxes for you. We offer real-time collaborative editin

Disclaimer, I'm on AFFiNE's team. But I really think you can check us out as I think we can cover those boxes for you. We offer real-time collaborative editing which also works offline. We deal with all those conflict issues for you. And though we aren't file-based, we do offer various export options such as MD, HTML, PDF and images. We expect to have the latest Docker version and real-time collaboration available towards the end of this month. In the mean time I'd invite you to try the client to see how it feels.