The UI would be the same except the tab would be fixed a specific conversation. Perhaps worth an experiment. I know the purist UX view would want to adapt it t

The UI would be the same except the tab would be fixed a specific conversation. Perhaps worth an experiment. I know the purist UX view would want to adapt it to then make the new tabs seamless and so on but I would expect most users just really want to have tabs per conversation or chat or thread and be able to cycle tabs instead of cycling conversations using shortcuts. You are discounting how much comfort the brain gets from a mental model you are used to, and the most common app for people to use is the web browser, which works with tabs for conceptual separation of topics, which is a great analog to different conversations or threads.