[rlander]

Maybe you haven’t seen this yet, but there is a (recent) option to fork a conversation when you click on the thee dots of a reply.

[davorak]

I think I have always been able to have branching conversations via editing a comment.

The interface remembers both the old and new conversation thread and you can switch between them.

It seems like the new "Branch in new chat" feature mostly creates a new chat at the top level rather then the existing functionality of editing a comment and branching in the same chat.