the ability to star / bookmark messages (eg like WhatsApp)
make messages in group chats pinnable for everyone (either like Discord or like Telegram)
While I agree with this keep in mind that those are just server events not the server log.
In my opinion they could add events prior to your connection (usually to be found in the server log) to the event history when the user has the permissions to view the log while making a clear distinction between events that occurred since you are connected and earlier ones.
All of the above are good suggestions, though it may be more appriopriate to wait and see the roadmap before we comment? I’m sure this topic has been causing sleepless nights to someone in the dev and design teams so they might have already thought of a solution