about (2), we did experiment enabling the new Real Time Collaboration feature of JupyterLab, but it turns out it's not production-ready yet so we disabled it. however, the good news is that https://github.com/jupyterlab/jupyterlab/pull/11599 is about to be merged very soon, which means that the next release of JupyterLab will probably have a robust RTC feature we can try out