What is pending in CodeMirror next?

I am searching for a decent web editor for a my upcoming project. I need to choose between codemirror5/ CodeMirror next. Description says CodeMirrorNext is WIP; simple demo seems working fine. What exact features/fixes pending in comparison to codemirror5?

Did a bit more research on GitHub issues, found it is worth waiting for an official release.

Yes, there’s a lot of stuff that’s still being designed and very little real-world testing has happened, so trying to start using it in production is likely to still be very painful.