The underlying issue to me is the different velocity of different conversations between the same people in a room. Conversation 1 can be fast, with short messages and informal, Conversation 2 can be slow, with long technical messages or attached files. And all in between.

Sometimes one type of convo transforms into another. And the tool should reframe it so: either by providing a schism for a new thread, changing the topic of the thread, or so.

This is something that tools with N-level threads, where each message creates a new thread (technical email discussions with top posting) do very well. I wish that each message would create a new thread. And that the UX allowed to me pivot from short and informal to long and thought out messages easily.

From an informal conversation of the daily, to starting a thread from a message, where we discuss a technical implementation in a long comment. And then back to someone opening an informal thread starting from a phrase of that long comment (ala document reviews).